Evidence changes

AutismUpdateOctober 31, 2026

A separate section was added to the page for children with intellectual disability and severe behavior problems. The only controlled study testing pure CBD on this question is an 8-child pilot study (Efron 2021): its aim was to test whether such a study is feasible; the authors reported a signal in favor of CBD, but the number of children was far too small for a conclusion, and all the children taking CBD were autistic. There is no controlled study giving a separate result for intellectual disability without autism. The results of the large 132-child study and of a 20-person pilot study with nabilone in adults had not been published as of October 2026. In autism, the result and the strength of evidence did not change.

Cancer TreatmentUpdateOctober 31, 2026

Five observational studies (head and neck, lung and bladder cancer) looking at the course of the disease in people who were using or had previously used cannabis when they were diagnosed with cancer were added to the table, and a separate paragraph describing them was written in the “What does the research say?” section: no clear difference was seen in survival, in cancer coming back or in a second cancer developing; in lung cancer, aggressive tumor types were more common in people who smoked tobacco along with cannabis. Because these studies are observational, they do not show cause and effect, and the strength of evidence is very weak. For a 2025 publication claiming that there is a “scientific consensus” that cannabis is good for cancer, a question and answer was added explaining what it did and why it does not count as evidence of a treatment. Because the result of a short report on cannabis use disorder and death in colon cancer could not be read, and the abstract of the same research group's larger study gives no figures for cannabis either, both are described under unverifiable items. The result and the strength of evidence did not change.

PTSDUpdateOctober 31, 2026

The Turkey question now adds that dronabinol and nabilone, which were tested in PTSD studies, are not licensed in Turkey: the list of licensed medicines of the Turkish Medicines and Medical Devices Agency (October 16, 2026) contains no medicine containing cannabinoids, and neither drug is on the agency's list of active substances from abroad (September 28, 2026) either. The result and the strength of evidence did not change.

MS SpasticityUpdateOctober 31, 2026

A separate section on MS-related tremor was added to the page. In the only randomized study that looked specifically at tremor (Fox 2004; 14 people, oral cannabis extract), there was no difference from placebo on objective tests measuring tremor; in the 160-person study with the mouth spray containing THC and CBD (Wade 2004), there was also no difference in the tremor measurement. An old 8-person THC study without a comparison group (Clifford 1983) and a 2022 systematic review that did not recommend cannabis-based medicines for MS tremor (Pourmohammadi 2022) were also added to the table. Pure CBD has never been tested in MS-related tremor; the evidence for tremor is weak. For spasticity, the conclusion and the strength of evidence did not change.

AutismUpdateOctober 30, 2026

The correction to the Wilson 2026 meta-analysis published in the journal was read: the results did not change. According to the corrected table, the meta-analysis's autism result rests on 2 studies done with products containing both THC and CBD; there is no study done with CBD alone. This information was added to the page.

Related studies: Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged), PROSPERO CRD42023392718)

PTSDUpdateOctober 30, 2026

The correction to the Wilson 2026 meta-analysis published in the journal was read: only the axis of one figure and the study counts in a table were corrected; the results on this page did not change.

Related studies: Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged))

SchizophreniaUpdateOctober 30, 2026

Information from two large observational meta-analyses was added to the 'Who should be careful' section: the link between cannabis use in people diagnosed with schizophrenia and suicide attempts and, in follow-up studies, the risk of death by suicide (Mulligan 2025), and the onset of psychosis an average of 2.5 years earlier in people who use cannabis (Stevens 2026). Both show an association, not cause and effect; they were not added to the table as rows, and their sources are given within the items. The conclusion and the strength of evidence did not change.

SchizophreniaUpdateOctober 30, 2026

The correction published in the journal for the Wilson 2026 meta-analysis was read: only the axis of one figure and the study counts in a table were corrected; the results on this page did not change.

Related studies: Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged))

DementiaUpdateOctober 30, 2026

It was added to the question about Turkey that dronabinol and nabilone, which were tested in dementia studies, are not licensed in Turkey: there is no cannabinoid-containing medicine on the Turkish Medicines and Medical Devices Agency's list of licensed medicines (October 16, 2026), and neither drug appears on the agency's list of active substances from abroad (September 28, 2026). The conclusion and the strength of evidence did not change.

Dravet SyndromeUpdateOctober 28, 2026

On October 28, 2026, two sources found for this page during the searches for other topics were read from their primary sources. Weight loss numbers from the US product information of the approved CBD medicine were added to the side effects list: in the Dravet and Lennox–Gastaut controlled studies, the share of patients whose weight fell by at least 5% from baseline was 16% in the CBD group and 8% in the placebo group; this share was higher at the high dose. The 2021 position paper of the Brazilian Academy of Neurology was reviewed; it was not added to the page because it brought no new data and reported study results differently from their sources. The registry results of the extension study in the table were checked again against ClinicalTrials.gov and found correct. The conclusion and the strength of evidence did not change.

Dravet SyndromeUpdateOctober 28, 2026

In October 2026, PubMed, Cochrane and ClinicalTrials.gov were systematically searched again (1295 PubMed and 46 ClinicalTrials.gov records reviewed; findings were reread from primary sources in an independent check). Studies added: a meta-analysis combining Dravet only (Lattanzi 2020), two network meta-analyses indirectly comparing Dravet medicines (Lattanzi 2023, Guerrini 2024), a manufacturer analysis by clobazam use (Devinsky 2020), the three-year extension of the two RCTs (Scheffer 2021), three drug-level studies measuring interactions with stiripentol, valproate and clobazam (Ben-Menachem 2020 and VanLandingham 2020 in patients, Morrison 2019 in healthy volunteers), everyday-practice studies from France, Italy and England (D'Onofrio 2020, Cerulli Irelli 2025, Perulli 2025, Lelli 2026; in adults, Silvennoinen 2021), use without clobazam (Nabbout 2023), unapproved cannabis extracts (Press 2015) and a THC-containing cannabis oil (McCoy 2018). Added to the evidence summary: that Cochrane's Dravet review does not include CBD, the clobazam and stiripentol subgroups, indirect comparisons with limited certainty against other Dravet medicines, long-term and everyday-practice data, and a sentence describing the search itself; the box and strength of evidence for THC-containing products were written for the first time (Insufficient). The two Lattanzi 2020 reviews in the table were distinguished by name; response rates, outcomes with no difference and company ties were added to the GWPCARE2 row. No new efficacy RCT was found. The conclusion and the strength of evidence did not change.

Related studies: Lattanzi 2020 (Dravet meta-analysis), published March 2020 (PMID 32040850, doi:10.1007/s40263-020-00708-6); Lattanzi 2023 (network meta-analysis), published October 2023 (PMID 37695433, doi:10.1007/s40265-023-01936-y); Guerrini 2024 (network meta-analysis, approved doses), published April 2024 (PMID 38427284, doi:10.1002/epi4.12923); Devinsky 2020 (clobazam subgroups), published December 2020 (PMID 32592183, doi:10.1111/ane.13305, Gunning 2021, PMID 32969022, in Dravet, ratio of convulsive seizures vs. placebo 0.71 (95% CI 0.60–0.83) in all patients, 0.63 (0.52–0.77) with clobazam, OR for a reduction of at least half 2.34 (1.51–3.63) and 2.78 (1.62–4.77), 3 of the 7 authors are employees of the manufacturer, 4 are consultants or investigators for the manufacturer); Scheffer 2021 (GWPCARE5, Dravet), published October 2021 (PMID 34406656, doi:10.1111/epi.17036, NCT02224573, separate results for Dravet in the registry, posted in February 2022). Interim analysis: Devinsky 2019, PMID 30582156, median 274 days, transaminases ≥3×ULN in 22 of 128 patients (17.2%) from GWPCARE1, all taking valproate, stopping because of side effects 6.4%, median reduction in convulsive seizures 38–44% up to week 48); Ben-Menachem 2020 (stiripentol and valproate interaction, in patients), published June 2020 (PMID 32350749, doi:10.1007/s40263-020-00726-4, NCT02607891, NCT02607904); VanLandingham 2020 (clobazam interaction, in patients), published October 2020 (PMID 32652616, doi:10.1002/jcph.1634, NCT02565108); Morrison 2019 (clobazam, stiripentol and valproate interaction), published November 2019 (PMID 30791225, doi:10.1002/cpdd.665); D'Onofrio 2020 (France, slow titration), published August 12, 2020 (PMID 32903409, doi:10.3389/fneur.2020.00829); Nabbout 2023 (use without clobazam), published August 2023 (PMID 37331197, doi:10.1016/j.seizure.2023.05.003); Cerulli Irelli 2025 (real world, SCN1A/Dravet subgroup), published July 2025 (PMID 40126049, doi:10.1111/epi.18378); Perulli 2025 (real world, Italy), published December 2025 (PMID 41165013, doi:10.1002/epi4.70149); Silvennoinen 2021 (adult Dravet, England), published October 2021 (PMID 34052628, doi:10.1016/j.seizure.2021.05.014); Lelli 2026 (status epilepticus, Italy), published November 2026 (online August 16, 2026) (PMID 42636610, doi:10.1016/j.seizure.2026.08.011); Press 2015 (unapproved cannabis extracts), published April 2015 (PMID 25845492, doi:10.1016/j.yebeh.2015.02.043, Overlapping cohort from the same center: Treat 2017, PMID 27859038, a Dravet diagnosis was linked to shorter use (p=0.02), per parent report, response 24%, side effects 19%); McCoy 2018 (THC-containing cannabis oil), published September 2018 (PMID 30250864, doi:10.1002/acn3.621, NCT02983695, no results in the registry))

Lennox–Gastaut SyndromeUpdateOctober 28, 2026

On October 28, 2026, four sources found for this page during the searches for other topics were read from their primary sources. The separate final Lennox–Gastaut results on ClinicalTrials.gov for the extension study lasting up to three years (Patel 2021) were added to the table and the evidence summary: 243 of 366 patients completed the study; the median reduction in drop seizures over each patient's last 12 weeks, including those who left early, was 59%; serious side effects occurred in 157 patients, and 12 deaths were recorded (the registry does not state whether the deaths were related to the medicine). These results come from a study without a comparison group and are not a peer-reviewed publication. Weight loss figures from the US product information for the approved CBD medicine were added to the side effects list: in controlled studies, the proportion of patients whose weight decreased by at least 5% was 16% in the CBD group and 8% in the placebo group. A small, uncontrolled series of 12 patients with a Lennox–Gastaut-like picture in 15q duplication syndrome (in the same direction as the larger studies in the table) and a 2021 position paper of the Brazilian Academy of Neurology (which brings no new data and reports study results differently from their sources) were reviewed and not added to the page. The conclusion and strength of evidence did not change.

Tuberous SclerosisUpdateOctober 28, 2026

On October 28, 2026, three sources found for this page during the searches for other topics were read in their primary sources. Weight loss figures from the US prescribing information of the approved CBD medicine were added to the side effects list: in the tuberous sclerosis study, the share of patients whose weight dropped by at least 5% from baseline was 31% in the CBD group and 8% in the placebo group. The 9 tuberous sclerosis patients in a real-world study from Germany were not added to the page because their seizure results were not reported separately, and the Brazilian Academy of Neurology's 2021 position paper was not added because it brought no new data for tuberous sclerosis. The conclusion and the strength of evidence did not change.

Drug-Resistant EpilepsyUpdateOctober 28, 2026

In October 2026, PubMed, Cochrane and ClinicalTrials.gov were systematically searched again (3,670 PubMed and 119 ClinicalTrials.gov records were screened; findings were reread from primary sources in an independent check). 27 studies added: a placebo-controlled study in focal seizures with CBDV, a compound closely related to CBD (Brodie 2021; seizures fell similarly to placebo), and the small 1980 CBD study (Cunha 1980); the Cochrane review (Gloss 2014), two systematic reviews specific to these epilepsies (Lattanzi 2021, Coppola 2026), a meta-analysis comparing CBD-rich extracts with pure CBD (Pamplona 2018) and the UK's national guideline (NICE 2019); childhood absence epilepsy (a study with results only in the registry), epileptic spasms over 2 years of age, CDKL5 deficiency and Rett, epilepsy with myoclonic-atonic seizures, 15q duplication and Angelman, Sturge–Weber and FIRES series, and CBD gel on the skin in developmental and epileptic encephalopathies; real-world data on off-label use from Germany, France, Denmark and Colombia; studies with THC-containing or CBD-rich products from the US (a prospective study and a state program), Israel, Colombia and Thailand; product content analyses from Chile and the US, and European side effect reports. Later publications from the same programs or studies with overlapping patients were added to the 'other sources' section of the relevant rows; one row's result was written out with numbers. A sentence describing the search itself was added to the evidence summary. No new efficacy RCT with purified oral CBD was found in these epilepsies. The conclusion and the strength of evidence did not change.

Related studies: Cunha 1980, published 1980 (PMID 7413719, doi:10.1159/000137430, A review that also describes the same trial: Carlini and Cunha 1981, PMID 7028792, improvement in 7 of the 8 patients taking CBD and in 1 patient taking placebo)); Brodie 2021 (CBDV, focal seizures), published December 2021 (PMID 33998885, doi:10.1089/can.2020.0075, NCT02365610, no results in the registry or PubMed). The journal added a correction note for Figure 2 (April 15, 2021)); Gloss 2014 (Cochrane), published March 5, 2014 (PMID 24595491, doi:10.1002/14651858.CD009270.pub3, PMID 22696383, PMID 7413719, a separate row in the table), PMID 3941934, letter to the editor), Trembly 1990 (conference abstract only)); Lattanzi 2021 (epilepsies other than Dravet and LGS), published March 2021 (PMID 33754312, doi:10.1007/s40263-021-00807-y); Coppola 2026 (DEE and complex drug-resistant epilepsies), published February 2026 (PMID 41558068, doi:10.1016/j.eplepsyres.2026.107731, PMID 41820159, content not on PubMed, could not be read). Non-seizure outcomes from the same systematic search: Samanta 2026, PMID 42520581, 32 studies, 1, 343 patients, most studies reporting improvements in cognitive function, behavior, communication and quality of life were observational and at moderate-to-high risk of bias, same authors and same company ties)); Pamplona 2018 (CBD-rich extracts and pure CBD), published September 2018 (PMID 30258398, doi:10.3389/fneur.2018.00759, Correction: Front Neurol 2018, PMID 30687209, PMC6335388, numbers in Tables 2 and 4 and the abstract were corrected, according to the authors, the conclusion did not change)); NICE 2019 (NG144 guideline), published November 11, 2019 (PMID 31909928, Evidence review D: epilepsy (NICE, November 2019, PMID 35107910, NBK577085). Guideline: nice.org.uk/guidance/ng144); Absence epilepsy, synthetic CBD (NCT03336242) (NCT03336242, 2023), NCT03355300, results June 18, 2023). No peer-reviewed publication of this study was found in PubMed (October 28, 2026)); Scheffer 2021 (CBD gel on the skin, developmental and epileptic encephalopathy), published September 2021 (PMID 34477852, doi:10.1001/jamanetworkopen.2021.23930, ACTRN12618000516280); Kaplan 2017 (Sturge-Weber syndrome), published June 2017 (PMID 28454984, doi:10.1016/j.pediatrneurol.2017.02.009, NCT02332655, collaborators Jazz Pharmaceuticals and the Faneca 66 Foundation). Later study by the same team: Smegal 2023, PMID 36508880, NCT04447846, no seizures were seen, and improvements in neurological score, quality of life and anxiety were reported, on the working memory test, the registry's primary outcome, the mean T score changed from 37.1 to 39.1 in 7 patients (no statistics given), 1 patient stopped because of a moderate side effect, open-label and uncontrolled); Gofshteyn 2017 (FIRES), published January 2017 (PMID 27655472, doi:10.1177/0883073816669450); Kühne 2023 (Germany, 16 centers), published June 2023 (PMID 36693811, doi:10.1002/epi4.12699, Later off-label use study from some of the same centers (some patients may be shared): Hollander 2025, PMID 40696489, 6 centers in Germany, 2019–2023, the Frankfurt, Freiburg, Greifswald and Lingen centers and 5 of the 10 authors are also in Kühne 2023, LGS, Dravet and TSC patients were not included): 108 patients (74 focal onset, 14 genetic generalized, 20 other epilepsies, 76 adults), at month 3, seizures fell by at least half in 42 of the 108 patients who started (38.9%), retention 61% at month 12, side effects 38%, discontinuation in which side effects played a role 19.5%, seizure counts rely on diaries kept by caregivers, no control group, the study was not funded, and 9 of the 10 authors reported fees from pharmaceutical companies, including Jazz, the maker of the approved medicine); Calonge 2024 (Paris, adults), published November 2024 (PMID 39501537, doi:10.1002/brb3.70122); Espinosa-Jovel 2023 (Colombia, other than LGS, Dravet and TSC), published November 2023 (PMID 37769547, doi:10.1016/j.seizure.2023.09.015); Zilmer 2021 (Denmark), published April 28, 2021 (PMID 33913416, Dan Med J 2021, 68(5):A07200527); Cerulli Irelli 2026 (15q duplication and Angelman syndrome), published June 2026 (PMID 41992447, doi:10.1002/epi4.70241); Vignoli 2025 (typical Rett syndrome and CDKL5 deficiency), published August 2025 (PMID 40543048, doi:10.1002/epi4.70078, Monogenic epilepsy study partly from the same centers (6 shared centers and authors, periods overlap): Cerulli Irelli 2025, PMID 40126049, 27 centers, at least 3 months of CBD): in the CDKL5 (12 patients) and MECP2 (12 patients) groups, the proportion of patients whose seizures fell by at least half was 33.3%, some of the patients are very likely shared with those in this row. The same study is a separate row in the Dravet and TSC tables); Caraballo 2023 (epilepsy with myoclonic-atonic seizures), published June 2023 (PMID 37182500, doi:10.1016/j.yebeh.2023.109245); González-Alguacil 2026 (epileptic spasms over age 2), published January 2026 (PMID 41197417, doi:10.1016/j.pediatrneurol.2025.10.013); Devinsky 2022 (medical cannabis containing THC), published April 2022 (PMID 35267245, doi:10.1002/acn3.51537); Navarro 2023 (adult focal epilepsy, compounded CBD+THC), published January 2023 (PMID 36129615, doi:10.1007/s10072-022-06393-1); Uliel-Sibony 2021 (Israel, 20:1 oil, tolerance), published January 2021 (PMID 32713661, doi:10.1016/j.braindev.2020.06.018, Earlier study from the same center: Hausman-Kedem 2018, PMID 29674131, 20:1 oil, 57 patients, 46 in the efficacy analysis, mean CBD 11.4 mg/kg/day, median follow-up 18 months, side effects 46% and the main reason for stopping, better response in children under 10 years of age and with doses above 11 mg/kg/day, the response rate sentence in the abstract ('26 patients (56%) ≤50% reduction') is unclear). Retrospective study of 5 Israeli pediatric neurology clinics, including this center: Tzadok 2016, PMID 26800377, 74 children, 20:1 CBD:THC oil, CBD 1–20 mg/kg/day, mean 6 months, according to family reports, more than 50% seizure reduction in 38 children (52%), stopped in 5 children (7%) due to increased seizures, one of the authors works at a cannabis company and one at the Ministry of Health's medical cannabis unit). Some of the patients in the three studies are very likely shared); Lusawat 2025 (Thailand, CBD-rich oil), published August 2025 (PMID 40460512, doi:10.1016/j.pediatrneurol.2025.04.015); Lyu 2026 (Minnesota medical cannabis program), published December 2026 (online August 2026) (PMID 42612572, doi:10.1016/j.yebeh.2026.111230); Ríos-Pohl 2024 (Chile, product analysis), published December 2024 (PMID 39503571, doi:10.1002/epi4.13081); Gidal 2024 (US commercial CBD products), published March 2024 (PMID 38562466, doi:10.3389/fphar.2024.1335441); Calapai 2024 (unlicensed CBD, European side effect reports), published January 2024 (PMID 37800192, doi:10.1002/ptr.8028)

AutismUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during searches for other topics were read and added to the page. A later sub-analysis (Medeiros 2026) of the 60-child controlled study in Brazil (Silva 2024) had been listed as a separate row in the table; because it is a second publication of the same trial, it is no longer a separate row, and its finding (no difference from placebo in facial expression recognition and theory of mind in 19 children who completed the social cognition tests) was moved to the main study's row. The number of controlled studies did not change; the conclusion and the strength of evidence did not change.

AutismUpdateOctober 28, 2026

In October 2026, PubMed (835 records), Cochrane and ClinicalTrials.gov (87 records) were systematically searched again. The scope was widened and a fragile X syndrome section was added to the page: a 212-child controlled study with pure CBD gel applied to the skin (no different from placebo on the primary outcome; a difference only in an exploratory subgroup analysis added afterward), a 20-child open-label study and a 240-child long-term open extension study. A second large controlled study in this subgroup has ended, but its results have not been published; because the company's announcement about this study could not be verified, it was mentioned only under unverifiable points. A real-world study from Israel's national data was also added (share of children who continued treatment for a year about 26%). The result for THC-containing products was rewritten to describe all four controlled studies. Corrected: the upper limit of the average doses reached in the studies (5.9, not 7.88 mg/kg/day) and that in the controlled studies with pure CBD the dose was fixed at 10–20 mg/kg/day; two publications from the same Israeli group of children were not counted as separate studies and were moved to the row of the main study (Hacohen 2022); the other publications of the single-dose brain imaging study were added; a study's company ties, confidence interval and number of children analyzed; a meta-analysis's number of participants and correction notice; a publication's year. The strength of evidence did not change.

Related studies: Berry-Kravis 2022 (CONNECT-FX), published November 25, 2022 (PMID 36434514, doi:10.1186/s11689-022-09466-6, NCT03614663, confirmatory study RECONNECT, NCT04977986, ended August 29, 2025, as of October 2026, no results in the registry and no peer-reviewed publication)); Heussler 2019 (FAB-C), published August 2, 2019 (PMID 31370779, doi:10.1186/s11689-019-9277-x, ACTRN12617000150347); Berry-Kravis 2025 (fragile X extension), published November 18, 2025 (PMID 41254489, doi:10.1186/s11689-025-09657-x, NCT03802799, no results as of October 2026)); Treves 2025 (Israeli national data), published November 21, 2025 (PMID 41357860, doi:10.3389/fphar.2025.1646560)

Chemotherapy NauseaUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during the searches for other topics were read and added to the page. The scope was broadened to include nausea during radiation therapy (radiotherapy), and the title was changed accordingly; PubMed and ClinicalTrials.gov were also searched separately for this section. 4 rows were added to the table: 2 studies with nabilone in radiotherapy nausea (one placebo-controlled, one comparing it with metoclopramide) and 1 older comparative study with THC; and the UK's national guideline NICE (2019; nabilone may be considered as add-on treatment in adults for chemotherapy nausea that continues despite standard medicines). A warning about cannabis hyperemesis syndrome was added. The rule that experimental synthetic cannabinoids do not enter the table as rows (October 28, 2026) was also applied to the 4 older chemotherapy studies on this page with levonantradol, which was never approved: the rows were removed from the table, their findings are mentioned in the evidence summary as background, and the numbers were corrected accordingly. A single-arm study looking at the tolerability of dronabinol in glioma patients, with results only on ClinicalTrials.gov (NCT00314808), was not included in the table because it had no comparison group and tracked nausea only as a secondary outcome. The conclusion and the strength of evidence did not change.

Related studies: NICE 2019 (NG144 guideline), published November 11, 2019 (updated March 22, 2021) (PMID 31909928, Evidence review A: persistent nausea and vomiting (NICE, November 2019, PMID 35107906, NBK577077). Guideline: nice.org.uk/guidance/ng144); Côté 2016 (radiotherapy), published April 2016 (PMID 26503964, doi:10.1177/0003489415612801, Funding: Canadian public research funds, nabilone and placebo were supplied by the manufacturer, the authors reported no conflicts of interest (as reported in Cochrane 2023)); Priestman 1987 (radiotherapy), published September 1987 (PMID 2822337, doi:10.1016/s0009-9260(87)80151-4, Dose, group size, side-effect percentages and bias assessment: NICE NG144 evidence review A (November 2019), Appendix E and Appendix H.2. Nabilone was supplied by the manufacturer (Eli Lilly)); Ungerleider 1984 (radiotherapy), published February 1984 (PMID 6318262, doi:10.1148/radiology.150.2.6318262, Full text could not be read (publisher site returned 403))

Cancer PainUpdateOctober 28, 2026

October 2026 additional review: a source found for this page during the searches for other topics was read and added to the page. The sleep result in the low-dose group was added to the dose study of the THC and CBD mouth spray in cancer pain not responding to opioids (Portenoy 2012): the score for pain interfering with sleep, a secondary measure, decreased more than with placebo only at the low dose, with no difference at the medium and high doses; on the study's primary outcome, there was also no difference between the spray and placebo. The conclusion and the strength of evidence did not change.

Cancer PainUpdateOctober 28, 2026

In the October 2026 search (PubMed, Cochrane, ClinicalTrials.gov), 20 studies were added to this topic: 9 randomized studies (two single-dose THC studies from 1975, Lynch 2014, Côté 2016, Turcott 2018, Zylla 2021, D'Andre 2024, Zylla 2026 CanPan and the ointment study in joint pain), the registry results of the 6-month open-label extension study of nabiximols, the MASCC, ASCO and BMJ guidelines, 2 systematic reviews and 5 observational studies. Registry numbers, funding and company ties, and the figures from Cochrane and from the registry results, were added to the rows of the nabiximols studies; the page now states that the measures referred to as 'quality of life' were global impression and satisfaction questionnaires, that the positive subgroup findings in US patients were post hoc and went in both directions, and that more deaths occurred in the spray group during the randomized period of one study (the authors and the independent safety board saw no link with the spray); the pain data reported by Cochrane were added to the MedCan1 row. The sentence based on the ESMO 2018 guideline was removed from the evidence summary and moved to the unverifiable points because the full text of the guideline could not be accessed; completed studies whose results have not been published were also listed under the unverifiable points. The conclusion and the strength of evidence did not change; the scope of the strength of evidence for THC was clarified.

Related studies: Noyes 1975 (THC–codeine comparison), published July 1975 (PMID 50159, doi:10.1002/cpt197518184, Listed as 'Noyes 1975a' in Cochrane 2023. Funding: clinical research center support from the US National Institutes of Health (NIH). The same team's dose–response study: Noyes 1975 (THC dose–response), in this table); Noyes 1975 (THC dose–response), published February–March 1975 (PMID 1091664, doi:10.1002/j.1552-4604.1975.tb02348.x, Listed as 'Noyes 1975b' in Cochrane 2023. Funding: US National Institutes of Health (NIH)); Lynch 2014, published January 2014 (PMID 23742737, doi:10.1016/j.jpainsymman.2013.02.018, NCT00872144, no funding, the authors declared no conflicts of interest); Côté 2016, published April 2016 (PMID 26503964, doi:10.1177/0003489415612801, Funding: Canadian public research funds (CIHR, FRSQ), the manufacturer provided nabilone and placebo (as reported in Cochrane 2023)); Turcott 2018, published September 2018 (PMID 29550881, doi:10.1007/s00520-018-4154-9, NCT02802540); Zylla 2021, published December 2021 (PMID 34085149, doi:10.1007/s00520-021-06301-x, Products were provided free of charge through the state program. 2 of the 13 authors are affiliated with medical cannabis manufacturers in the state (PubMed affiliation information). Letter of criticism in the journal: Davis 2022, PMID 35083541, in this table); D'Andre 2024, published December 2024 (PMID 39016024, doi:10.1089/can.2023.0253, NCT05388058); Zylla 2026 (CanPan), published January 9, 2026 (PMID 41510814, doi:10.1200/OP-25-01165, NCT06605430, 16-week dose-response analysis: Gupta 2026, PMID 42767994, funding by donation, no conflicts of interest reported. The same group's stage 4 cancer study: Zylla 2021, in this table); Zylla 2026 (ointment for joint pain), published February 2026 (online December 2025) (PMID 41467893, doi:10.1177/25785125251398286, NCT05935891, the ointments were provided free of charge by a medical cannabis company, the authors declared no conflicts of interest); NCT01337089 (nabiximols long-term open-label extension, registry results), published April 23, 2018 (registry results) (NCT01337089, April 23, 2018, no publication found on PubMed in October 2026). The sponsors in the registry are Jazz Pharmaceuticals, the drug's current owner, and its development partner Otsuka. Main studies: Fallon 2017 and Lichtman 2018 (in this table)); To 2023 (MASCC guideline), published March 6, 2023 (PMID 36872397, doi:10.1007/s00520-023-07662-1, PMID 37148393, does not affect the results). No funding was received for the guideline (publisher's page). The same society's guideline on anxiety, depression and insomnia in cancer: De Feo 2023, PMID 36809575); Braun 2024 (ASCO guideline), published May 1, 2024 (PMID 38478773, doi:10.1200/JCO.23.02596, Q&A summary: Braun 2024, PMID 38478793); Busse 2021 (BMJ Rapid Recommendation), published September 8, 2021 (PMID 34497062, doi:10.1136/bmj.n2040, Underlying systematic review: Wang 2021, PMID 34497047, the average pain analysis of Wang 2021 included only one cancer pain study); Creangă-Murariu 2026 (meta-analysis of opioid use), published June 9, 2026 (PMID 42262611, doi:10.1007/s00520-026-10856-y, PROSPERO CRD420251175971. Funding: research fund of a Romanian public health program, the authors declared no conflicts of interest); Creangă-Murariu 2025, published September 2025 (PMID 40748522, doi:10.1007/s11912-025-01695-x, PROSPERO CRD42023479375); Maida 2008, published March 2008 (PMID 18402303); Aviram 2022, published May 2022 (PMID 35669038, doi:10.3389/fpain.2022.861037, 1-month study by the same group: Aviram 2020, PMID 33265945, pain intensity improved, no difference in pain between THC- and CBD-dominant products, worst and least pain had not changed significantly at month 1). Funding: a charitable foundation, the authors declared no conflicts of interest); Aprikian 2024 (Quebec Cannabis Registry), published January 2024 (PMID 37130724, doi:10.1136/spcare-2022-004003, Analysis of symptoms and sex differences in the same 358 patients: Kasvis 2022, PMID 35723729); Varadpande 2025 (UK Medical Cannabis Registry), published June 2025 (PMID 39921589, doi:10.1080/15360288.2025.2457101, Preliminary 16-patient palliative care report from the same registry: Nimalan 2022, PMID 34980282); Stienrut 2024 (Thai national cohort), published July 17, 2024 (PMID 39144529, doi:10.1159/000540153, Thai Clinical Trials Registry TCTR20191231001. Funding: the Department of Thai Traditional and Alternative Medicine of the Ministry of Health, which also makes the product, the authors declared no conflicts of interest)

Appetite Loss in CancerUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during the searches for other topics were read and added to the page. The nabilone dose in the Côté 2016 row was corrected based on the study characteristics table of Cochrane 2023 (after week 3, at most 2 mg/day, at most 4 tablets a day; the previous wording "at most 1 mg twice a day" was a review's interpretation). A cohort without a comparison group that followed 2,873 cancer patients in Thailand for 3 months (Stienrut 2024; about 0.2 mg of THC a day) was added; the improvement seen in the appetite-loss score cannot be attributed to the product because the dose was so low and the study was uncontrolled. The conclusion and the strength of evidence did not change.

Related studies: Stienrut 2024 (Thai national cohort), published July 17, 2024 (PMID 39144529, doi:10.1159/000540153, Thai Clinical Trials Registry TCTR20191231001. Funding: the Department of Thai Traditional and Alternative Medicine of the Ministry of Health, which also makes the product, 9 of the 13 authors work in this department, the authors declared no conflicts of interest)

Appetite Loss in CancerUpdateOctober 28, 2026

The source of the side-effect information in the Côté 2016 and Turcott 2018 rows is now stated clearly: both are taken from the table of a systematic review (Ceolin 2024); the full texts of the studies could not be read. The conclusion and the strength of evidence did not change.

Sleep and Anxiety in CancerUpdateOctober 28, 2026

October 2026 supplementary review: sources found for this page during the searches for other topics were read and worked into the page. A cohort without a comparison group that followed 2,873 cancer patients in Thailand for 3 months (Stienrut 2024; about 0.2 mg of THC a day) was added: quality of life and anxiety scores improved, but an improvement seen at such a low dose and without controls cannot be attributed to the product; sleep was not measured separately in this study. The side-effect information for the single-dose pre-imaging CBD study in breast cancer (Nayak 2024) was completed from the full text (mild or moderate nausea in 2 people in the CBD group, pain in one of them; no side effects with placebo). The conclusion and the strength of evidence did not change.

Related studies: Stienrut 2024 (Thai national cohort), published July 17, 2024 (PMID 39144529, doi:10.1159/000540153, Thai Clinical Trials Registry TCTR20191231001. Funding: the Department of Thai Traditional and Alternative Medicine of the Ministry of Public Health, which also makes the product, 9 of the 13 authors work in this department, the authors reported no conflicts of interest)

Sleep and Anxiety in CancerUpdateOctober 28, 2026

In the October 2026 search (PubMed, Cochrane, ClinicalTrials.gov), 24 studies were added to this topic: 9 studies with a comparison group (7 placebo-controlled: Davies 1974, Strasser 2006, Brisbois 2011, Côté 2016, Turcott 2018, Weiss 2025, Haney 2025; waitlist-controlled Zylla 2026; Schloss 2021, comparing two THC:CBD ratios), 1 open-label study (Fleege 2025), 7 systematic reviews including the MASCC 2023 guideline and Cochrane 2023, and 7 observational studies. The THC result for sleep was updated with the Cochrane analysis of cancer pain studies (no difference or a very small improvement); the negative sleep result of two small RCTs with CBD-dominant products was added. The statement 'there is no THC RCT for anxiety' was corrected: there are RCTs that measured anxiety as a secondary measure, and they found no difference; a small 1974 THC pilot in anxious patients was also added. Quality of life and real-world data were described together with their limits; ASCO 2024's weak recommendation against high-dose CBD for symptom burden was added. Anxiety, depression and quality-of-life results, registration numbers and funding were added to the MedCan rows; an internal file note visible to readers in two places was removed. The conclusion and the strength of evidence did not change.

Related studies: Davies 1974, published August 1974 (PMID 22454883, doi:10.1111/j.1365-2125.1974.tb00257.x); Strasser 2006 (Cannabis-In-Cachexia-Study-Group), published July 20, 2006 (PMID 16849753, doi:10.1200/JCO.2005.05.1847); Brisbois 2011, published September 2011 (PMID 21343383, doi:10.1093/annonc/mdq727, NCT00316563, no results in the registry)); Côté 2016, published April 2016 (PMID 26503964, doi:10.1177/0003489415612801, Funding: Canadian public research funds, the manufacturer supplied the nabilone and placebo (as reported by Cochrane 2023)); Turcott 2018, published September 2018 (PMID 29550881, doi:10.1007/s00520-018-4154-9, NCT02802540, quality-of-life domains were secondary outcomes, no results in the registry). The manufacturer donated the nabilone and placebo and had no role in the study (as reported by Cochrane 2023)); Schloss 2021, published May 2021 (PMID 34094937, doi:10.3389/fonc.2021.649555, ANZCTR ACTRN12617001287325. Funding: the company that supplied the product (Bioceuticals), the authors reported no conflicts of interest); Zylla 2026 (CanPan), published January 9, 2026 (PMID 41510814, doi:10.1200/OP-25-01165, NCT06605430, 16-week dose–response analysis: Gupta 2026, PMID 42767994, funding was a donation, no conflicts of interest reported); Weiss 2025, published October 2025 (PMID 41211445, doi:10.3389/fonc.2025.1590168, NCT04398446, the authors reported no conflicts of interest); Haney 2025, published October 2025 (PMID 40611810, doi:10.1089/can.2025.0028, NCT03782402, results in the registry)); Fleege 2025, published August 2025 (PMID 40751295, doi:10.1002/cam4.71117, NCT04754399, PROMIS anxiety T score −3.4, depression −1.7). Funding: public and foundation funds); De Feo 2023 (MASCC guideline), published February 21, 2023 (PMID 36809575, doi:10.1007/s00520-023-07628-3); Crichton 2024, published June 2024 (PMID 38430618, doi:10.1016/j.maturitas.2024.107941); Creangă-Murariu 2025, published September 2025 (PMID 40748522, doi:10.1007/s11912-025-01695-x, PROSPERO CRD42023479375); Häuser 2023 (Cochrane), published June 5, 2023 (PMID 37283486, doi:10.1002/14651858.CD014915.pub2); AminiLari 2022, published February 14, 2022 (PMID 34546363, doi:10.1093/sleep/zsab234); Belgers 2023, published February 2023 (PMID 35861789, doi:10.1089/can.2021.0187, Brain tumor study by the same research group: Belgers 2026 (in this table)); Simon 2022, published February 2022 (PMID 34881518, doi:10.1002/jcsm.12861); Maida 2008, published March 2008 (PMID 18402303); Bar-Lev Schleider 2018, published March 2018 (PMID 29482741, doi:10.1016/j.ejim.2018.01.023); Aviram 2022, published May 2022 (PMID 35669038, doi:10.3389/fpain.2022.861037, 1-month study from the same research group: Aviram 2020, PMID 33265945, THC-dominant products were better than CBD-dominant ones only for sleep duration). Funding: a charitable foundation, the authors reported no conflicts of interest); Reddy 2026 (Minnesota cannabis program), published April 2026 (PMID 41120744, doi:10.1007/s12094-025-04069-8, Anxiety and depression analysis in the same 1, 962 patients: Reddy 2025, PMID 41163433, analysis of cancer patients' symptoms over the first 4 months in the same program: Anderson 2019, PMID 30860938, the authors reported no conflicts of interest); Kasvis 2022 (Quebec Cannabis Registry), published October 2022 (PMID 35723729, doi:10.1007/s00520-022-07193-1, Pain analysis of the same 358 patients: Aprikian 2024, PMID 37130724); Bar-Sela 2013, published July 2013 (PMID 23956774, doi:10.1155/2013/510392); Varadpande 2025 (UK Medical Cannabis Registry), published June 2025 (PMID 39921589, doi:10.1080/15360288.2025.2457101, Preliminary 16-patient palliative care report from the same registry: Nimalan 2022, PMID 34980282)

Cancer TreatmentUpdateOctober 28, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were systematically searched; 17 studies were added: 2 clinical studies with products containing THC and CBD (glioma and chronic lymphocytic leukemia), a 119-patient pure CBD case series, the ASCO 2024 guideline, 3 reviews (one Cochrane) and 10 observational studies comparing cancer patients who use and do not use cannabis (6 in people receiving immunotherapy; results conflicting). The case series and observational studies reporting positive results were written up together with their methodological limitations and the authors' company ties. Registry numbers, the main publication, doses, death counts and company ties were added to existing rows; ARISTOCRAT's target number of patients was corrected according to verified sources. The texts on immunotherapy were balanced to also show the studies that found no difference, and the warning from the MASCC 2023 guideline was added; statements saying 'no human study' that conflicted with the table were corrected to 'no well-designed human study'; time-dependent statements were written with dates; a transparency sentence was added to the evidence summary. The conclusion and the strength of evidence did not change.

Related studies: Schloss 2021, published May 21, 2021 (PMID 34094937, doi:10.3389/fonc.2021.649555, ANZCTR ACTRN12617001287325); Melén 2022, published June 2022 (PMID 35037561, doi:10.1080/10428194.2021.2020776, EudraCT 2014-005553-39 (EU Clinical Trials Register: completed, no results section)); Kenyon 2018, published October 2018 (PMID 30275207, doi:10.21873/anticanres.12924, The same author's breast, prostate and glioma follow-up publications are not in PubMed, assessed in the Guggisberg 2022 row); Braun 2024 (ASCO guideline), published May 1, 2024 (PMID 38478773, doi:10.1200/JCO.23.02596, Q&A summary: Braun 2024, PMID 38478793); McBain 2021 (Cochrane, recurrent glioblastoma), published May 4, 2021 (PMID 34559423, doi:10.1002/14651858.CD013579.pub2); Rodriguez-Almaraz 2020 (systematic review and meta-analysis), published July 2020 (PMID 32765889, doi:10.1093/nop/npaa013); Guggisberg 2022 (assessment of case reports), published February 2022 (PMID 34370591, doi:10.1089/can.2021.0045); Coschi 2025 (CCTG pooled analysis), published March 2025 (PMID 40184324, doi:10.1080/1750743X.2025.2485012, Trials: CCTG BR.34, CO.26, PA.7, IND.226); Waissengrin 2023, published February 2023 (PMID 36535195, doi:10.1016/j.ejca.2022.11.022); Taha 2019, published April 2019 (PMID 30670598, doi:10.1634/theoncologist.2018-0383, Independent reanalysis: Piper 2024, PMID 38610922); Bar-Sela 2020, published August 28, 2020 (PMID 32872248, doi:10.3390/cancers12092447, PMID 35454955, Table 1), independent reanalysis: Piper 2024, PMID 38610922); Hadid 2024, published December 2024 (PMID 39737331, doi:10.1177/25151355241309095); Alsavaf 2025, published October 2025 (PMID 39704258, doi:10.1111/ajco.14135); Peleg Hasson 2024, published April 1, 2024 (PMID 38242547, doi:10.1136/ijgc-2023-004953); Gastmeier 2024, published March 14, 2024 (PMID 38655402, doi:10.1159/000538311); Phansila 2022, published October 3, 2025 (version 3) (PMID 41113085, doi:10.12688/f1000research.123250.3, F1000Research first version 2022, version 3 October 3, 2025); Gallow 2026, published March 13, 2026 (PMID 41939176, doi:10.1159/000550792)

Pain After SurgeryUpdateOctober 28, 2026

The October 2026 search added 31 studies, and on October 28, 2026 the scope was widened so that postoperative nausea and vomiting joined this page as a separate section. Added: a pilot RCT of pure CBD in bilateral knee replacement (Sideris 2026) and a CBD pilot study in tooth extraction; three experimental pain studies with CBD-containing products; ten controlled studies of THC-containing drugs and nabilone for postoperative and acute pain (including the two knee replacement RCTs published in 2026; the results of two are only on ClinicalTrials.gov) and an uncontrolled dose-escalation study; four controlled studies in postoperative nausea (one only in the registry); two systematic reviews in acute pain and one in experimental pain; a review summarizing postoperative pain in cannabis users; recommendations from the American, Canadian and São Paulo anesthesia societies; four observational studies. Registry numbers, figures and confidence intervals were added to the Bebee, Narang, Chrepa, Haffar, Schneider, Dieterle and Abdallah rows; the single significant difference against CBD in Haffar 2022 was written into its row. The topic text was updated for the new studies, the nausea section and the search counts. The conclusion and the strength of evidence did not change.

Related studies: Sideris 2026, published October 22, 2026 (PMID 42913966, doi:10.1016/j.jpain.2026.106477, NCT04749628, May 26, 2026)); Abidi 2025 (SWAP), published November 25, 2025 (PMID 41471281, doi:10.3390/ph18121792, NCT04271917, before the study started, the registry lists 68 participants as 'actual', with no results posted, the May 2, 2022 date in the article is the record's last update)); De Vita 2022, published October 2022 (PMID 34251840, doi:10.1037/pha0000465); Bergeria 2025, published February 28, 2025 (PMID 40839659, doi:10.1097/j.pain.0000000000003561, NCT04036968); Gorbenko 2024, published November 2024 (PMID 39054656, doi:10.1002/cpt.3381); NCT03825965 (Busse pilot, registry results), published September 8, 2026 (registry results) (NCT03825965, September 8, 2026), protocol: Busse 2026, PMID 42032682, doi:10.21203/rs.3.rs-9622221/v1); Thor 2026, published May 2026 (PMID 41838938, doi:10.1097/ALN.0000000000005945, NCT04734080, March 27, 2026)); Jennings 2026, published July 2026 (PMID 41967982, doi:10.1016/j.arth.2026.02.047, NCT04298528, unilateral knee replacement, preoperative cannabis screening, same dose, the registry plans 460 people, drug for 4 weeks, primary outcome 30-day opioid use, status 'unknown', no registry number in the abstract, match could not be confirmed)); NCT05820685 (DOPE, registry results), published June 11, 2025 (registry results) (NCT05820685, June 11, 2025, no publication found in PubMed in October 2026)); Kumar 2024, published April 2024 (PMID 38765405, doi:10.7759/cureus.58566); Seeling 2006, published April 2006 (PMID 16389542, doi:10.1007/s00101-005-0963-6); Buggy 2003, published November 2003 (PMID 14581124, doi:10.1016/s0304-3959(03)00331-2); Beaulieu 2006, published August 2006 (PMID 16873343, doi:10.1007/BF03022793); Holdcroft 2006, published May 2006 (PMID 16645457, doi:10.1097/00000542-200605000-00021); Raft 1977, published January 1977 (PMID 832447, doi:10.1002/cpt197721126, PMID 1062533, published in the same period with the same design: anxiety, dysphoria, paranoid thinking and tachycardia with IV THC premedication, no superiority of THC over diazepam or placebo (whether it is the same study could not be confirmed)); Colwill 2020, published June 2020 (PMID 32459420, doi:10.1097/AOG.0000000000003850, NCT03604341); Levin 2017, published April 2017 (PMID 28160217, doi:10.1007/s12630-017-0814-3, NCT02115529); Kleine-Brueggeney 2015, published November 2015 (PMID 26426861, doi:10.1213/ANE.0000000000000877, NCT00695487, the registry's study director is an author of the article, same dose and timing, in the registry it was stopped on the grounds that 'no effect was seen at interim analysis', and the participant count shows as 320, versus 40 in the article, no registry number in the abstract)); Lewis 1994, published August 1994 (PMID 7917745, doi:10.1093/bja/73.2.244); NCT00757822 (US Veterans Affairs, registry results), published May 13, 2016 (registry results) (NCT00757822, May 13, 2016, no publication found in PubMed in October 2026)); Gazendam 2020, published December 2020 (PMID 33381643, doi:10.1089/can.2019.0079); Stevens 2017, published March 2017 (PMID 28090652, doi:10.1111/aas.12851); De Vita 2018, published November 2018 (PMID 30422266, doi:10.1001/jamapsychiatry.2018.2503); King 2026, published February 2026 (PMID 41406677, doi:10.1016/j.jclinane.2025.112097); Shah 2023 (ASRA guideline), published March 2023 (PMID 36596580, doi:10.1136/rapm-2022-104013); Ladha 2021 (Canadian PAIN consensus), published January 2021 (PMID 33129489, doi:10.1016/j.bja.2020.09.026); de Barros 2024 (São Paulo Society of Anesthesiology), published July–August 2024 (PMID 38740135, doi:10.1016/j.bjane.2024.844513); Hickernell 2018, published December 2018 (PMID 30170713, doi:10.1016/j.arth.2018.07.027); Schneider-Smith 2020, published February 2020 (PMID 32154376, doi:10.1136/tsaco-2019-000391, NCT03928015, protocol Swartwood 2020, PMID 32178232); Layeeque 2006, published June 2006 (PMID 16720146, doi:10.1016/j.amjsurg.2005.07.040); Suhre 2020, published May 18, 2020 (PMID 32423445, doi:10.1186/s12871-020-01036-4)

Neuropathic PainUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during searches for other topics were read and added to the page. The full text of the brachial plexus injury study (Kittithamvongs 2025) was read: the product tested was a cannabis oil containing roughly equal amounts of THC and CBD, dropped under the tongue; the product type changed from 'Other' to 'Contains THC', dose information was added, and the number of randomized studies with products containing THC rose from 27 to 28. Added: the numerical inconsistencies in the publication to the study of an oil applied to the skin in nerve pain from diabetes (Seevathee 2025); the authors’ company ties, and the fact that the study the review counts as 'oral CBD' most likely also contained a small amount of THC, to the review of chemotherapy-induced neuropathy (Datta 2026); and the appetite hormone substudy of the same trial to the HIV-associated neuropathy study (Ellis 2009). A separate search was done for complex regional pain syndrome and a short section was added: there is no controlled study specific to this condition; three short studies in mixed nerve pain groups also included these patients, and their numbers were written in two rows; a 64-patient series with no comparison group from the UK medical cannabis registry was added to the table. The views of guidelines and expert bodies were added to the evidence summary: both those recommending against use and those writing that cannabinoids may be considered when other treatments have not been enough. An uncontrolled CBD study in chemotherapy-induced neuropathy (Vigano 2025) was not added to the table: patients had not been selected for nerve pain, and no pain result was reported for the period when CBD was given alone. The conclusion and the strength of evidence did not change.

Related studies: Evans 2025 (UK Medical Cannabis Registry, complex regional pain syndrome), published September 2025 (PMID 40898690, doi:10.1002/brb3.70823, PMC12405601)

Chronic PainUpdateOctober 28, 2026

October 2026 additional review: sources found for this page in the searches of other topics were read and worked into the page. The number of people in the medical cannabis card study (Gilman 2022) was corrected (269 people randomized, 186 analyzed), and the daily survey analysis of the same trial was added; for the CBD study in patients with chronic pain on methadone treatment (Costa 2026), it was noted that the primary outcomes in the registry differed from those in the article, that the manufacturer supplied the product, and the registry number was added. Two suggestions were reviewed and not added to the table: a study measuring the effect of THC on experimental pain in people on methadone treatment (participants were not selected for chronic pain), and a 2020 meta-analysis that overlaps with the more recent reviews in the table. The conclusion and the strength of evidence did not change.

Chronic PainUpdateOctober 28, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were searched systematically; 33 studies were added: 13 randomized studies in non-cancer chronic pain (nabilone, dronabinol, purified THC, vaporized inhaled cannabis, THC:CBD oil, two pragmatic studies in which cannabis use was assigned by lottery, and an open-label study comparing a THC-dominant extract with opioids in chronic low back pain; including three studies with results only in the registry: CBD in endometriosis and in opioid users, and cannabis in opioid users), 7 systematic reviews (including the 2026 update from the US Agency for Healthcare Research and Quality and reviews on opioid reduction, long-term safety and comparisons of cannabis with opioids), the UK's national guideline (NICE), the American College of Physicians' (ACP) 2025 recommendation, and 11 observational or uncontrolled studies, including studies that measured opioid use through prescription records. In the topic text, the effect on chronic pain and lowering the opioid dose were described separately, a transparency sentence was added, and a reader-visible reference to an internal file was removed. In existing rows: the chronic low back pain study's withdrawal phase with a negative result and its company ties, the product type of two reviews ('mixed,' because they pooled more than one product), the number of people in one review, and the laboratory and observational findings of the opioid reduction review were added; the fibromyalgia study was aligned with its row on that topic. The conclusion and the strength of evidence did not change.

Related studies: Notcutt 2004, published May 2004 (PMID 15096238, doi:10.1111/j.1365-2044.2004.03674.x); Pinsger 2006, published June 2006 (PMID 16855921, doi:10.1007/s00508-006-0611-4); Narang 2008, published March 2008 (online December 2007) (PMID 18088560, doi:10.1016/j.jpain.2007.10.018, NCT00153192, PMID 24281276, 10 and 20 mg dronabinol increased mind-altering effects more than placebo on 4 of 5 subscales, with peak effects similar to smoked marijuana)); de Vries 2016, published March 2016 (online January 2016) (PMID 26505163, doi:10.1111/bcp.12811, NCT01318369); de Vries 2017, published July 2017 (online October 2016) (PMID 27720917, doi:10.1016/j.cgh.2016.09.147, NCT01562483); Abrams 2020, published July 1, 2020 (PMID 32678452, doi:10.1001/jamanetworkopen.2020.10874, NCT01771731); Kliuk-Ben Bassat 2023, published April 2023 (online December 2022) (PMID 37007688, doi:10.1093/ckj/sfac275); Gilman 2022, published March 1, 2022 (PMID 35302633, doi:10.1001/jamanetworkopen.2022.2106, NCT03224468, PMID 36638745, 181 people, 12 weeks, cannabis use frequency rose in those who got the card, reported sleep quality was better on days of use, no improvement in pain or depressive symptoms)); Meissner 2025 (VER-01, comparison with opioids), published December 2025 (online September 30, 2025) (PMID 41028525, doi:10.1007/s40122-025-00773-z, NCT05610813, EudraCT 2022-001358-41); NCT04527003 (endometriosis, registry results), published April 4, 2025 (registry results) (NCT04527003, 2025, no publication found in the October 2026 search)); Chesterman 2025, published November 2025 (online September 23, 2025) (PMID 41005282, doi:10.1016/j.ctcp.2025.102023); NCT04760613 (CBD in opioid users, registry results), published September 19, 2024 (registry results) (NCT04760613, 2024, no publication found in the October 2026 search)); Abrams 2011, published December 2011 (online November 2011) (PMID 22048225, doi:10.1038/clpt.2011.188, NCT00308555); Chou 2026 (AHRQ living review update), published February 2026 (online December 23, 2025) (PMID 41429020, doi:10.7326/ANNALS-25-03152, PMID 40956916, search April 28, 2025, 29 RCTs and 15 observational studies, oral pure CBD did not reduce pain: 4 RCTs, 334 people, difference 0.40, 95% CI −0.14 to 1.00, moderate certainty, evidence insufficient for its effect on opioid use), PMID 35667066); Stockings 2018, published October 2018 (PMID 29847469, doi:10.1097/j.pain.0000000000001293); Noori 2021, published July 28, 2021 (PMID 34321302, doi:10.1136/bmjopen-2020-047717); Zeraatkar 2022, published August 4, 2022 (PMID 35926992, doi:10.1136/bmjopen-2021-054282); Bialas 2022, published July 2022 (online May 2022) (PMID 35467781, doi:10.1002/ejp.1957); Fink 2026, published July 1, 2026 (online April 17, 2026) (PMID 42061001, doi:10.1016/j.drugalcdep.2026.113167); NICE 2019 (NG144 guideline), published November 11, 2019 (updated March 22, 2021) (PMID 31909928, www.nice.org.uk, 2019, last updated March 22, 2021), PMID 35107907); Ware 2015 (COMPASS), published December 2015 (online September 2015) (PMID 26385201, doi:10.1016/j.jpain.2015.07.014, ISRCTN19449752); Campbell 2018 (POINT), published July 2018 (PMID 29976328, doi:10.1016/S2468-2667(18)30110-5); Goedel 2022, published February 2022 (online October 2021) (PMID 34695720, doi:10.1016/j.drugpo.2021.103502); Nguyen 2023, published January 3, 2023 (PMID 36716026, doi:10.1001/jamanetworkopen.2022.54573); Slawek 2026, published February 1, 2026 (PMID 41359313, doi:10.1001/jamainternmed.2025.6496, NCT04308148, NCT04495725, finished March 2024, result not published as of the October 2026 search)); Fontaine 2026, published 2026 (PMID 41267332, doi:10.1080/10826084.2025.2586250); Erridge 2026 (UK Medical Cannabis Registry), published October 2026 (PMID 42885647, doi:10.1002/jcph.70313, PMID 34937477, 190 patients), PMID 37021592, 761 patients), PMID 39545361, 1139 patients)); Überall 2026 (CARE, German Pain e-Registry), published 2026 (PMID 41821925, doi:10.2147/JPR.S551457, EU PAS EUPAS1000000490); Capano 2020, published January 2020 (online November 2019) (PMID 31711352, doi:10.1080/00325481.2019.1685298); NCT04827992 (cannabis in opioid users, registry results), published June 24, 2026 (registry results) (NCT04827992, 2026), PMID 35680252); Jeddi 2024, published January 3, 2024 (PMID 38171632, doi:10.1136/bmjopen-2022-068182); ACP 2025 (American College of Physicians recommendation), published May 2025 (online April 4, 2025) (PMID 40183677, doi:10.7326/ANNALS-24-03319); Vozoris 2024, published November 2024 (online August 14, 2024) (PMID 39141203, doi:10.1007/s11606-024-08978-2)

CBD Cream (Topical)UpdateOctober 28, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were systematically searched; 7 studies were added: 2 randomized studies with THC-containing products rubbed on the skin (a placebo-controlled study with a THC-dominant oil in diabetic neuropathy and a study without placebo comparing CBD and THC ointments in hand pain caused by a breast cancer medicine), a placebo-controlled study with a CBD paste applied to mouth ulcers (canker sores), 3 systematic reviews (one of them the US Agency for Healthcare Research and Quality's living review) and an absorption study in healthy volunteers that is the source of the drug test information on the page. Two small uncontrolled studies with products that also contained other pain relievers or undisclosed substances alongside CBD were not included in the table because the improvement could not be attributed to CBD. In existing rows: the product type of the cannabis extract ointment in jaw pain, of a CBD oil rubbed on the skin and of the CBD + myrcene gel used in vulvar pain became 'CBD-rich extract, THC content unclear'; it was written that the two positive jaw pain studies come from the same research group, that the first was registered retrospectively, that the second one's registration does not match the paper, and that an article thought to be an additional publication is a separate pilot study; it was added that the only significant difference in the knee replacement study was against CBD, along with the company ties and registration numbers of the hand osteoarthritis gel study and details of the chemotherapy neuropathy study; the incorrect 'no one dropped out' statement in the side effect summary was corrected. The conclusion and strength of evidence for THC-containing products were written for the first time (very weak). The conclusion and the strength of evidence did not change.

Related studies: Seevathee 2025, published 2025 (PMID 39720705, doi:10.1159/000542511, Thai Clinical Trials Registry TCTR20211220008); Zylla 2026, published February 2026 (online December 2025) (PMID 41467893, doi:10.1177/25785125251398286, NCT05935891); Chou 2025 (AHRQ living review), published July 2025 (PMID 40956916, doi:10.23970/AHRQEPCCER250UPDATE2025, NCBI Bookshelf NBK618045 (AHRQ report no. 25-EHC036), PROSPERO CRD42021229579, PMID 40238954, journal publication Chou 2026, PMID 41429020); Galant 2025 (systematic review), published December 17, 2025 (PMID 41463118, doi:10.3390/biomedicines13123110, PROSPERO CRD42025632021); Scholfield 2023 (systematic review), published August 2023 (online May 23, 2022) (PMID 35605018, doi:10.1089/can.2021.0154); Zamarripa 2024, published March 2024 (PMID 38217086, doi:10.1093/jat/bkae001, NCT04741477, no results in the registry)); Umpreecha 2023, published February 20, 2023 (PMID 36803360, doi:10.1186/s12906-023-03886-0, Thai Clinical Trials Registry TCTR20220802004 (retrospective registration, August 2, 2022))

AnxietyUpdateOctober 28, 2026

October 2026 additional review: sources found for this page in the searches for other topics were read and incorporated into the page. The product of the exam anxiety study (Stanley 2023) is, according to the trial registration, a CBD-rich extract; the row's product type was corrected accordingly to 'CBD-rich, THC content unclear', and the basis for the registration match was written down. In the row of the 178-person study in India (Gundugurti 2024), the role of the company the authors are affiliated with was corrected according to the conflict of interest statement and the pharmacokinetic publication of the same trial: it is not the company that developed the product, but the company that funded the pharmacokinetic part of the trial. The conclusion and the strength of evidence did not change.

AnxietyUpdateOctober 28, 2026

PubMed, Cochrane and ClinicalTrials.gov were systematically searched again in October 2026 (2,159 records in PubMed and 144 in ClinicalTrials.gov; together with an independent second check). Added: 8 controlled studies in patients or people experiencing anxiety or stress (one with results only in the trial registry; most found no difference from placebo), 3 lab studies in volunteers (including those showing THC's two-way effect on stress and anxiety and that its stress-reducing effect is similar to placebo), 3 meta-analyses and 5 observational studies. Older lab experiments and meta-analyses whose question is answered by a newer or larger study or review in the table were not added separately; the second publication reporting the sleep results of the same trial was removed as a separate row and moved to the main study's sources. Corrected: the company ties and unusually small standard error of the large India study, the fact that the match with the drug regulator's minutes is not certain, the patent ties of the Brazilian research group, the trial registrations and urine THC test results of the open-label studies, the statement 'only uncontrolled data exist' for THC-containing products, and the order of the table. The conclusion and the strength of evidence did not change.

Related studies: NCT02548559 (McLean Hospital, double-blind phase; registry results), published Not published; results in the registry March 27, 2026 (NCT02548559, results posted to the registry on March 27, PMID 36352103, in this table); Fabre 1981, published 1981 (PMID 6117575, doi:10.1002/j.1552-4604.1981.tb02617.x); Glass 1980, published 1980 (PMID 6108592, doi:10.1007/BF00434401, Other publications of the same study: Glass 1981, PMID 6117576, behavioral tasks added), PMID 373011); Gilman 2022, published March 1, 2022 (PMID 35302633, doi:10.1001/jamanetworkopen.2022.2106, NCT03224468); Nayak 2024, published December 2, 2024 (PMID 39680411, doi:10.1001/jamanetworkopen.2024.50391, NCT04482244); de Andrade Silva 2024, published December 2024 (PMID 39505200, doi:10.1016/j.joen.2024.10.010); Winkler 2025, published November 28, 2025 (PMID 41316488, doi:10.1186/s42238-025-00366-9, German Clinical Trials Register DRKS00030971 (preregistered on December 22, 2022)); Bidwell 2024, published August 2024 (online January 22, 2024) (PMID 38252547, doi:10.1089/can.2023.0187, NCT03491384, PMID 41752306, 30-day daily diary with flower and edible products, 345 people), PMID 40522823, PMID 40667474, 41864773), PMID 39458976, PMID 38608236); Nakano 1978, published January 1978 (PMID 22419, doi:10.1002/cpt197823154); Childs 2017, published August 1, 2017 (PMID 28599212, doi:10.1016/j.drugalcdep.2017.03.030); Cuttler 2026, published August 22, 2026 (online) (PMID 42632818, doi:10.1038/s41386-026-02533-9); Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged)); Bharat 2026, published November 2026 (online August 11, 2026) (PMID 42617303, doi:10.1016/j.psychres.2026.117380); Bilbao 2022, published August 19, 2022 (PMID 35982439, doi:10.1186/s12916-022-02459-1, PROSPERO CRD42021229932); Rifkin-Zybutz 2023 (UK Medical Cannabis Registry), published August 2023 (PMID 37314478, doi:10.1007/s00213-023-06399-3, PMID 34937473, first 67 patients), PMID 38155535, same 302 patients, 12 months), PMID 39526700, 302 patients, comparison of product forms), PMID 38299624, a single producer's products, 120 patients)); Lee 2022, published June 2022 (online September 14, 2021) (PMID 34520280, doi:10.1177/07067437211043393); Martin 2021, published September 9, 2021 (PMID 34566726, doi:10.3389/fpsyt.2021.729800); Feingold 2018, published June 2018 (PMID 29486095, doi:10.1002/da.22735); Xue 2021, published February 2021 (PMID 32909828, doi:10.1177/0706743720952251)

Panic AttacksUpdateOctober 28, 2026

October 2026 supplementary review: sources found for this page during the searches for other topics were read and added to the page. The fear-conditioning substudy of the therapy study (Kwee 2022) was removed as a separate row because it is a secondary publication of the same trial; its finding, including the exploratory subgroup result in people taking antidepressants, was moved to the main study’s row. The product of the CO₂ study in healthy volunteers was re-examined: according to the study registration and the publication of another study registered with the same product code, it is a CBD isolate; the article’s own methods section could not be read, and the product type (pure CBD) did not change. The conclusion and strength of evidence did not change.

Social AnxietyUpdateOctober 28, 2026

October 2026 supplementary review: sources found for this page during the searches for other topics were read and worked into the page. In three studies by the same Brazilian research group (Bergamaschi 2011, Crippa 2011, de Faria 2020), the authors' patent and company ties were written consistently with the other rows: the conflict-of-interest statement where it could be read, an explicit note where it could not, and the date of the group's patent on a CBD derivative. No studies were added to the table. The conclusion and the strength of evidence did not change.

Social AnxietyUpdateOctober 28, 2026

PubMed, Cochrane and ClinicalTrials.gov were systematically searched again in October 2026 (1,185 records on PubMed, 85 on ClinicalTrials.gov; together with an independent second check). Added: 3 controlled studies comparing CBD with placebo in social stress, speaking or social exclusion tasks (in people with Parkinson's disease, people at high risk of psychosis and healthy volunteers; two found no difference), a social stress study with THC in healthy volunteers, a CBD study in young people without a control group, 2 systematic reviews specific to social anxiety, the most recent meta-analysis of cannabinoid trials in mental disorders, 1 meta-analysis looking at cannabis use and social anxiety risk, and 1 follow-up study. A review repeating the same question, a second analysis of the same national data and a virtual reality experiment that did not measure social anxiety were not added separately. Corrected: the primary outcome of the therapy study was written out with numbers and with its sub-study; the source of anxiety in the imaging study, the authors' patent and company ties in two laboratory studies, blood pressure and pulse measurements, the statistical inconsistency in the Japanese study and the basis for the product in a case report were added; the conclusion and strength of evidence for THC-containing products were written for the first time; the search numbers were added to the evidence summary. The conclusion and the strength of evidence did not change.

Related studies: Arndt 2017, published 2017 (PMID 28861510, doi:10.1089/can.2017.0014); Childs 2017, published August 1, 2017 (PMID 28599212, doi:10.1016/j.drugalcdep.2017.03.030); Appiah-Kusi 2020, published April 2020 (PMID 31915861, doi:10.1007/s00213-019-05442-6, Main trial: Bhattacharyya 2018, PMID 30167644, relationship between cortisol and brain function from the same trial: Davies 2022, PMID 34480630); de Faria 2020, published February 2020 (PMID 31909680, doi:10.1177/0269881119895536); Berger 2022, published August 3, 2022 (PMID 35921510, doi:10.4088/JCP.21m14130, ANZCTR ACTRN12617000825358); Fliegel 2022, published December 2022 (PMID 36875967, doi:10.1016/j.psycom.2022.100074); Andreoli 2026, published February 2026 (PMID 41388755, doi:10.1080/14737175.2025.2604303); Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged)); Xue 2021, published February 2021 (PMID 32909828, doi:10.1177/0706743720952251); Cougle 2015, published July–August 2015 (PMID 26022838, doi:10.1016/j.jpsychires.2015.05.004)

PTSDUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during the searches for other topics were read and incorporated into the page. Results of the study in which CBD or placebo was added to prolonged exposure therapy in veterans (NCT03518801) were entered on ClinicalTrials.gov on October 28, 2026; the study was added to the table with its registry results (96 people started; symptoms decreased in both groups, the groups were not compared statistically, no peer-reviewed publication), and the 'results not released' sentences were corrected. Because the nightmare studies also appear on the insomnia page, a reference to that page was added. The conclusion and the strength of evidence did not change.

Related studies: Ayers (NCT03518801, registry results) (NCT03518801, results October 28, 2026), protocol and statistical analysis plan in the registry (version 1.44, November 6, 2023), collaborating institution University of California San Diego)

PTSDUpdateOctober 28, 2026

In the October 2026 search (PubMed, Cochrane, ClinicalTrials.gov), 16 studies were added to this topic: 3 controlled studies (a 171-patient multicenter dronabinol study in PTSD-related nightmares, two laboratory studies with THC in people with PTSD), 3 systematic reviews, 2 guidelines (the 2023 guideline of the US Departments of Veterans Affairs and Defense, American Academy of Sleep Medicine 2018) and 8 observational studies (nabilone patient records, cannabis use and the course of PTSD in veterans, therapy outcomes in cannabis users, two patient registries in the UK). The conclusion and evidence text for THC-containing products were updated in light of the new nightmare study: two RCTs positive for nightmares ('moderate' in the evidence text), no clear difference in overall PTSD symptoms ('weak'). The two-way nature of the real-world data, the guideline recommendations, and registrations with unreleased results or left unfinished were added to the text. Registration numbers, PTSD outcome, funding, company ties and blinding information were added to five existing rows; the product type of the smoked cannabis study was corrected to 'THC-containing'. The conclusion and evidence labels ('Weak' for CBD, 'Weak' for THC-containing products) did not change.

Related studies: Roepke 2026, published September 2026 (online August 5, 2026) (PMID 42557458, doi:10.1038/s41591-026-04546-9, NCT04448808, October 28, 2026), PMID 37147642); Zabik 2023, published May 2023 (PMID 37088409, doi:10.1016/j.nlm.2023.107758, NCT02069366, PMID 32162103, in response to threat images, THC reduced amygdala reactivity in people with PTSD) and Pacitto 2022, PMID 35981598, 51 people, THC reduced negative emotion during emotional reappraisal)); Zabik 2026, published February 2026 (online October 16, 2024) (PMID 39412674, doi:10.1007/s00213-024-06702-w, NCT03008005, PMID 42463794, 37 people with PTSD), done under the same grant (R61MH111935) and with the same dose groups: THC reduced frontal brain activity during emotional reappraisal, negative emotion ratings did not change (abstract only)); Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged)); Aviram 2026, published May 29, 2026 (PMID 42210342, doi:10.1186/s42238-026-00451-7); Rodas 2024, published February 14, 2024 (PMID 38353645, doi:10.4088/JCP.23r14862, PMID 38353646); Schnurr 2024 (VA/DoD 2023 guideline), published March 2024 (PMID 38408360, doi:10.7326/M23-2757, Full guideline: VA/DoD Clinical Practice Guideline for the Management of Posttraumatic Stress Disorder and Acute Stress Disorder, June 2023 (healthquality.va.gov), Recommendations 20 and 32–33); Morgenthaler 2018 (AASM), published June 15, 2018 (PMID 29852917, doi:10.5664/jcsm.7178); Fraser 2009, published 2009 (PMID 19228182, doi:10.1111/j.1755-5949.2008.00071.x); Cameron 2014, published October 2014 (PMID 24987795, doi:10.1097/JCP.0000000000000180); Wilkinson 2015, published September 2015 (PMID 26455669, doi:10.4088/JCP.14m09475, PMID 33035104, in 1, 413 veterans using nonprescribed opioids, cannabis use neither improved nor worsened PTSD symptoms over 4 months)); Metrik 2022, published February 2022 (online June 17, 2020) (PMID 32546286, doi:10.1017/S003329172000197X); Bonn-Miller 2022, published April 2022 (online December 9, 2020) (PMID 33998874, doi:10.1089/can.2020.0056); Hill 2024, published March 2024 (PMID 38266511, doi:10.1016/j.janxdis.2024.102827); Lynskey 2024, published March 12, 2024 (PMID 38468390, doi:10.1192/bjo.2024.13, PMID 39474239, 58 patients prescribed THC-rich flower, improvement in symptoms reported at months 3 and 6, all 3 authors work at the cannabis company Khiron or a clinic linked to it)); Datta 2025, published May 2025 (online April 18, 2025) (PMID 40235073, doi:10.1080/14737175.2025.2490539, PMID 36503404, 162 patients, 6 months, 88.9% had used cannabis before, a total of 220 side effects in 33 people (20.4%), most common insomnia and tiredness))

InsomniaUpdateOctober 28, 2026

October 2026 supplementary review: sources found for this page during the searches for other topics were read and added to the page. The product type of the review pooling cannabinoid trials in disturbed sleep (AminiLari 2022) was changed to 'mixed', because besides THC-containing products it also covers nabilone and CBDV studies; an internal note in a dose field was rewritten in reader language; the Brazilian Academy of Neurology’s 2025 Parkinson’s guideline assessment of CBD in REM sleep behavior disorder was added to the text; in three rows from the same Brazilian research group, the authors’ patent and company ties were written consistently with the other rows. No studies were added to the table. The conclusion and strength of evidence did not change.

InsomniaUpdateOctober 28, 2026

October 2026 evidence search: PubMed, Cochrane and ClinicalTrials.gov were searched systematically, and the findings were reread from primary sources in an independent check; by the founder’s scope decision, sections on sleep apnea and restless legs syndrome were opened on this topic. 27 studies were added to the table. In insomnia: a 2-week study with pure CBD in worried people (no different from placebo), a small 1981 study and a CBD gel applied inside the mouth; with THC-containing products, a sleep lab study in healthy volunteers, the cannabis card trial, two studies from Thailand and a multi-ingredient supplement study; nabilone and CBG studies; a meta-analysis, the Brazilian Sleep Association guideline and a patient registry from the UK. In sleep apnea, four studies with dronabinol, the American Academy of Sleep Medicine position statement and a systematic review; in restless legs, an open-label study, a review and the German guideline. In nightmares linked to post-traumatic stress disorder, two placebo-controlled studies with dronabinol and nabilone and the American Academy of Sleep Medicine nightmare position statement (also on the PTSD page) were added. Three rows that were secondary publications of the same trials, and a Parkinson’s trial in which sleep was only a secondary measure, were removed from this topic’s table; the findings of the secondary publications were moved to the main rows. Corrected in existing rows: that the primary measure was negative in a CBN study (Bonn-Miller 2024), that superiority over placebo stated in the abstract of a formula study was not seen in the full-text analysis (Hausenblas 2025), participant numbers, durations, registration numbers and company ties. The conclusion and strength of evidence did not change.

Related studies: Carlini 1981, published 1981 (PMID 7028792, doi:10.1002/j.1552-4604.1981.tb02622.x); Nicholson 2004, published June 2004 (PMID 15118485, doi:10.1097/01.jcp.0000125688.05091.8f); Ware 2010, published February 2010 (PMID 20007734, doi:10.1213/ANE.0b013e3181c76f70, NCT00381199, also a row in the fibromyalgia topic); Gilman 2022, published March 1, 2022 (PMID 35302633, doi:10.1001/jamanetworkopen.2022.2106, NCT03224468, PMID 36638745, in card holders, reported sleep quality was better on days cannabis was used, and frequency of use rose). Also a row in the pain, depression and substance use topics); Kolobaric 2023, published August 30, 2023 (PMID 37686820, doi:10.3390/nu15173788, NCT05511818, according to the publication, not this study’s own registration, Kolobaric 2024 in the table also cites the same template)); Peball 2022, published August 2022 (PMID 35937495, doi:10.1002/mdc3.13471, PMID 32757413, row in the Parkinson’s topic), NCT03769896, EudraCT 2017-000192-86, PMID 38491070, uncontrolled, 22 patients)); Walczyńska-Dragon 2025, published July 19, 2025 (PMID 40732351, doi:10.3390/ph18071064, PMID 38592260, row in the topical CBD topic), NCT05562635, no sleep measure)); Emerson 2026, published 2026 (PMID 41574318, doi:10.1159/000549902, NCT05088018); Gournay 2026, published April 2026 (PMID 41678223, doi:10.1037/pha0000832, PMID 37552290, row in the anxiety topic), this publication is also in the anxiety table under the name 'Gournay 2026 (sleep results)'); Kamoltham 2026, published February 24, 2026 (PMID 41736083, doi:10.1186/s42238-026-00415-x, Thai Clinical Trials Registry TCTR20240718004 (after the study ended)); Pakdee 2026, published December 2026 (journal volume; online earlier) (PMID 41623556, doi:10.1016/j.sleepx.2026.100173, PMID 41756111, PMC12933466): they acknowledge as limitations that no sleep apnea screening was done and that the analysis relied on within-group before–after change); Carley 2018 (PACE), published January 1, 2018 (PMID 29121334, doi:10.1093/sleep/zsx184, NCT01755091, PMID 29361189); Walsh 2025, published April 11, 2025 (PMID 39589391, doi:10.1093/sleep/zsae276, ANZCTR ACTRN12620000916943, PMID 40328187); Cousens 1973, published December 20, 1973 (PMID 4776660, doi:10.1007/BF00437513); Prasad 2013, published 2013 (PMID 23346060, doi:10.3389/fpsyt.2013.00001, PMID 24426820); Messineo 2023, published July 1, 2023 (PMID 36805833, doi:10.5664/jcsm.10528, NCT05101122); Lillo Triguero 2026, published July 2, 2026 (PMID 42387200, doi:10.1007/s00415-026-13975-y); Asim 2026, published December 2026 (journal issue; online earlier) (PMID 42574897, doi:10.1016/j.sleep.2026.109193, PMID 42753382, contents could not be read)); Drager 2023 (Brazilian Sleep Association), published October 2023 (PMID 38370879, doi:10.1055/s-0043-1776281); Ramar 2018 (AASM), published April 15, 2018 (PMID 29609727, doi:10.5664/jcsm.7070, PMID 30353820, PMID 30353823, 30353829 (contents not read)); Boylan 2024, published November 2024 (PMID 39498540, doi:10.1002/phar.4622); Saha 2026, published July 1, 2026 (PMID 42617004, doi:10.4103/aian.aian_1168_25, PMID 28655453, 6 patients), PMID 31820197, 12 patients), NCT06570941); Trenkwalder 2024 (German guideline), published November 6, 2024 (PMID 39501372, doi:10.1186/s42466-024-00353-0, Cannabinoids are not addressed in the American Academy of Sleep Medicine’s 2025 restless legs guideline (Winkelman 2025, PMID 39324694); Koye 2026 (UK Medical Cannabis Registry), published December 2026 (online October 26, 2026) (PMID 42935025, doi:10.1002/npr2.70180, PMID 38337193, 61 patients, PMID 41662070, 124 patients, 18 months)); Roepke 2026, published September 2026 (online August 5, 2026) (PMID 42557458, doi:10.1038/s41591-026-04546-9, NCT04448808, October 28, 2026), PMID 37147642, also a row in the PTSD topic); Jetly 2015, published January 2015 (PMID 25467221, doi:10.1016/j.psyneuen.2014.11.002, Health Canada registration, also a row in the PTSD topic); Morgenthaler 2018 (AASM), published June 15, 2018 (PMID 29852917, doi:10.5664/jcsm.7178, Also a row in the PTSD topic, PMID 32088375)

DepressionUpdateOctober 28, 2026

On October 28, 2026, two sources found for this page during the searches for other topics were incorporated. In the medical cannabis card study (Gilman 2022), the number of people was corrected: 269 people were randomly assigned to groups, and 186 were analyzed; the daily survey analysis of the same trial (Tervo-Clemmens 2023) was added, which also found no improvement in depression symptoms at 12 weeks. In the anxiety study in India (Gundugurti 2024), the description of the company tie was corrected in the table and the text: the authors' conflict-of-interest statement does not say that the company developed the product; according to the pharmacokinetic publication of the same trial, that part was funded by the pharmaceutical company where most of the authors worked. The trial registration and the pharmacokinetic publication were added to the table as sources. The conclusion and the strength of evidence did not change.

MigraineUpdateOctober 28, 2026

On October 28, 2026, a second, broader search was done (child and adolescent migraine, oral, inhaled and sublingual products, nabilone and dronabinol, patient registries, ClinicalTrials.gov results, guidelines and conference abstracts); no new study to add to the table was found. Added to the text: that a 30-person preliminary study comparing CBD with placebo in chronic migraine and a 79-person study comparing oral THC and CBD with a migraine medicine exist only as conference abstracts and could not be verified, an ongoing safety study in teenagers, and that the guidelines reviewed do not recommend cannabinoids; the wording 'oral CBD has not been tested in a controlled study' was clarified to 'there is no controlled study published as a full article.' The wording of the drug interaction notes was corrected. The strength of evidence did not change.

Crohn’s and Ulcerative ColitisUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during the searches for other topics were read and added to the page. The 2019 position statement of the Canadian Association of Gastroenterology was added to the table. Based on the evidence at the time it was written, the statement says that cannabis did not appear to change the course of Crohn’s disease and ulcerative colitis and that the evidence is insufficient to recommend it as a treatment that reduces inflammation; it also recommends that cannabis not be used in place of approved treatments. The statement is expert opinion without a formal grading of evidence. The evidence summary and the reviews paragraph were updated accordingly. The conclusion and the strength of evidence did not change.

Related studies: CAG 2019 (Andrews), published April 2019 (online November 8, 2018) (PMID 31294362, doi:10.1093/jcag/gwy064, PMC6507278 (full text read). According to the conflict-of-interest statement, 3 of the 7 authors have ties to companies that make cannabis or cannabinoid products (advisory board and executive role, research support and donated product, speaker fees and advisory board). The same document also appears in the irritable bowel and stomach table)

MS SpasticityUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during the searches for other topics were read and incorporated into the page. A separate section on bladder problems caused by MS was added: the only randomized study done specifically for the bladder (Kavia 2010; the mouth spray containing THC and CBD was no different from placebo in the main measure, urinary incontinence, and helpful on some secondary measures), the figures from the bladder part of the 630-person CAMS study (urinary incontinence decreased slightly more with cannabis extract and with THC than with placebo), the absence of a difference in bladder complaints in two large studies in the table, the loss of significance of the 2018 meta-analysis's very small bladder effect once manufacturer-supported studies were removed, two reviews on this topic (Abo Youssef 2017, Cheng 2026; both found the evidence weak), and the American Academy of Neurology's MS guideline reaffirmed in 2026 (the spray is probably ineffective for urinary incontinence); pure CBD has never been tested for this. Also added to the table: the UK NICE guideline's (2019) recommendation of a 4-week trial of the THC:CBD spray, and a controlled study showing that stopping improved thinking skills in people with MS who had smoked cannabis for a long time (Feinstein 2019). Assessed but not added: the Brazilian Academy of Neurology's 2021 position paper (adds no new information; its statement that the spray is approved in the US is incorrect) and a 19-person uncontrolled sleep study. For spasticity, the conclusion and the strength of evidence did not change.

Related studies: Kavia 2010, published November 2010 (online September 9, 2010) (PMID 20829244, doi:10.1177/1352458510378020, NCT00678795, the sponsor today is Jazz Pharmaceuticals)); Feinstein 2019, published September 1, 2019 (PMID 31363742, doi:10.1093/brain/awz213, Other publications from the same study: Feinstein 2021 (depression, PMID 32589554, Feinstein 2021 (cognitive awareness, PMID 34087949, PMC8413765), Meza 2024 (resting-state brain network, 33 people, PMID 38815510, and Meza 2024 (sex differences, 19 who stopped, PMID 39024968); Abo Youssef 2017, published April 2017 (online February 23, 2017) (PMID 28058780, doi:10.1111/bju.13759); Cheng 2026, published August 20, 2026 (PMID 42678682, doi:10.5489/cuaj.9478); NICE 2019 (guideline NG144), published November 11, 2019 (updated March 22, 2021) (PMID 31909928, www.nice.org.uk, 2019, last updated March 22, 2021, last reviewed May 20, 2025, recommendations 1.3.1–1.3.2, rationale section, research recommendation 5), PMID 35107908, NBK577084, could not be opened in this search)); Yadav 2014 (American Academy of Neurology), published March 25, 2014 (PMID 24663230, doi:10.1212/WNL.0000000000000250, Status: 'Reaffirmed on February 21, 2026' in the American Academy of Neurology guideline list (aan.com, October 28, 2026), the same academy's 2014 systematic review of medical marijuana (Koppel 2014, PMID 24778283, 2023 and is not in the table. PMC3962995 (abstract and author disclosures))

Parkinson’s DiseaseUpdateOctober 28, 2026

October 2026 supplementary review: sources found for this page during the searches for other topics were read and added to the page. The row for the study looking at the effect of a single dose of CBD on anxiety during a speaking test (de Faria 2020) was made consistent with the same study’s row on the Social Anxiety page: the placebo-controlled crossover design, the purity of the product (99.9% pure CBD powder), the participants’ sex and disease stage, public funding, and details of the tremor measurements (tremor amplitude went down; its frequency and slowness of movement did not change) were added from the tables of a systematic review; the results for the measured pulse and blood pressure could not be accessed. The same row now notes a CBD derivative patent that three of the authors reported in their other publications, and their university’s agreement with a pharmaceutical company to develop a synthetic CBD product, including for Parkinson’s disease. In the row for the small open-label study in Parkinson’s psychosis (Zuardi 2009), it is now stated clearly that the funding information could not be read from the primary source and came from a review table; it was added that the authors’ CBD patents date from the years after the study (consistent with the same row on the Schizophrenia page). The conclusion and the strength of evidence did not change.

Parkinson’s DiseaseUpdateOctober 28, 2026

PubMed, Cochrane and ClinicalTrials.gov were systematically searched again in October 2026 (1,464 records in PubMed and 270 in ClinicalTrials.gov; together with an independent second check). Added: 2 placebo-controlled randomized studies (a cannabis extract containing THC and CBD for levodopa-related involuntary movements, and pure CBD for REM sleep behavior disorder; neither differed from placebo), 3 systematic reviews and meta-analyses, the position paper of the Brazilian Academy of Neurology (together with the same academy’s 2025 Parkinson’s guideline), 5 studies without a comparison group (high-dose pure CBD, the 6-month extension study of nabilone, smoked marijuana, medical marijuana at doses patients adjusted themselves, a chart review of patients given medical marijuana in routine practice) and an observational comparison of long-term medical marijuana use. There is no Cochrane review on this topic. A small dose-finding study that did not measure efficacy and a guideline that was later withdrawn were not included in the table. Corrected: the CBD and THC amounts of the products in the studies, the numbers for primary outcomes, missing side effect information, company ties in two studies, additional publications and registration numbers of the same trials, and the table order; the explanation of the THC strength of evidence was updated in light of the new study (level unchanged). The conclusion and the strength of evidence did not change.

Related studies: Carroll 2004, published October 12, 2004 (PMID 15477546, doi:10.1212/01.wnl.0000140288.48796.8e, Commentary and author reply: Neurology 2005, PMID 15781848, content not read)); de Almeida 2021 (RBD), published July 2021 (PMID 33754375, doi:10.1002/mds.28577, PMID 35749710, 18 patients, 6 CBD / 12 placebo, no difference on primary and secondary outcomes). Both are also in the table for the Insomnia topic); Messak 2026, published May 15, 2026 (PMID 42138778, doi:10.1007/s13760-026-03082-0); Bilbao 2022, published August 19, 2022 (PMID 35982439, doi:10.1186/s12916-022-02459-1, PROSPERO CRD42021229932); Urbi 2022, published 2022 (PMID 34958046, doi:10.3233/JPD-212923); Brucki 2021, published April 2021 (PMID 34133518, doi:10.1590/0004-282X-ANP-2020-0432, Movement Disorders Department of the Brazilian Academy of Neurology, PMID 39993447, PMID 41173036, PMID 35319667); Leehey 2020, published December 15, 2020 (PMID 33381646, doi:10.1089/can.2019.0068, NCT02818777, February 19, 2019, the registry title says crossover RCT, but only the open-label first phase was done). The manufacturer (GW Research Ltd) is listed as a collaborator in the registry, the publication’s abstract states there was no conflict of interest); Peball 2024 (NMS-Nab2), published March 15, 2024 (PMID 38491070, doi:10.1038/s41531-024-00665-7, NCT03773796, March 2, 2021), the main trial is Peball 2020 in the table); Lotan 2014, published 2014 (PMID 24614667, doi:10.1097/WNF.0000000000000016); Anis 2026, published June 16, 2026 (PMID 42304702, doi:10.1177/25785125261458680, NCT05106504, same scales and product analysis, status “unknown” in the registry, no results entered), the publication’s abstract gives no registration number); Goldberg 2023, published July 2023 (PMID 37211456, doi:10.1016/j.parkreldis.2023.105406); Aladeen 2023, published May–June 2023 (PMID 37191563, doi:10.1097/WNF.0000000000000550)

SchizophreniaUpdateOctober 28, 2026

On October 28, 2026, sources found for this page during searches for other topics were processed. A systematic review looking at whether cannabis use further increases the risk of psychosis in people with ADHD (Suetani 2026; only 3 studies were found, and there is very little evidence of such an added risk) was added to the table and the text. Funding and company ties were re-examined for three older CBD studies from the Ribeirão Preto group in Brazil (Hallak 2010, Zuardi 2006, Zuardi 2009): Hallak 2010 was partly supported by public funds, the CBD was donated by a university researcher, and no company ties were declared in the article; the full texts of the other two studies could not be read, and for Zuardi 2009, the table of a systematic review lists public funds and two CBD manufacturers as supporters (the same information as the same row on the Parkinson's page); the CBD patents of three of the authors date from years after these studies. The conclusion and the strength of evidence did not change.

Related studies: Suetani 2026, published October 2026 (online March 31, 2026) (PMID 41916924, doi:10.1177/10398562261439662)

SchizophreniaUpdateOctober 28, 2026

PubMed, Cochrane and ClinicalTrials.gov were systematically searched again in October 2026 (5,768 records in PubMed, 416 in ClinicalTrials.gov; together with an independent second check). Added: 6 controlled studies of CBD in patients and people at high risk of psychosis (one with results only in the registry); very small uncontrolled series with CBD in treatment-resistant schizophrenia and Parkinson's psychosis and with CBD-rich medical cannabis in psychosis with cannabis use disorder; 2 studies in healthy volunteers testing whether CBD added to cannabis reduces THC's effects; 3 studies testing the effect of THC against placebo in patients and people at high risk of psychosis, and a small series in which THC was tried as a treatment; the Cochrane review and 8 more systematic reviews; one national guideline and one expert consensus report; 4 large observational studies on cannabis use and psychosis risk (including medical cannabis users). Reviews repeating the same question and studies covered by the reviews in the table were not added separately. Corrected: it was added that the difference in total symptom score in the largest CBD study was not significant, that the study was exploratory and that it was run by the maker; the later-published symptom results of the study in people at high risk of psychosis were written up with their limitations; the number of people in two studies, the result details and side effects of one study, the product type and sensitivity analysis of one meta-analysis, registry numbers and table order were corrected; a strength of evidence was added to the THC conclusion (insufficient for treatment; experimental and observational data pointing to harm). The conclusion and the strength of the CBD evidence did not change.

Related studies: NCT02504151 (Yale crossover study, registry results), published September 6, 2022 (registry results) (NCT02504151, 2022)); van Boxel 2023, published July 2023 (PMID 37207437, doi:10.1016/j.jpsychires.2023.05.019, NCT02932605); Köck 2021, published November 4, 2021 (PMID 34803760, doi:10.3389/fpsyt.2021.736822, NCT04700930); Hallak 2010, published March 2010 (PMID 20339735, doi:10.1590/s1516-44462010000100011); O'Neill 2021, published March 2021 (PMID 31994476, doi:10.1017/S0033291719003519, PMID 33860709, PMID 35775365, PMID 42552898); Bhattacharyya 2018, published November 1, 2018 (PMID 30167644, doi:10.1001/jamapsychiatry.2018.2309, ISRCTN46322781, symptom results: Bhattacharyya 2024 (World Psychiatry, PMID 39279373, letter), PMID 31915861, 1-week dosing and stress test), PMID 31439831, PMID 32921794, PMID 34480630, PMID 39145348, PMID 37845827, PMID 41337954); Zuardi 2006, published September 2006 (PMID 16401651, doi:10.1177/0269881106060967); Zuardi 2009, published November 2009 (PMID 18801821, doi:10.1177/0269881108096519, PMID 34104218, PMC8161868, Table 2)); Schipper 2018, published March 2018 (PMID 29039260, doi:10.1177/0269881117735684); Englund 2023, published May 2023 (PMID 36380220, doi:10.1038/s41386-022-01478-z, NCT05170217); Lawn 2023, published July 2023 (PMID 36750134, doi:10.1111/add.16154, NCT04851392); D'Souza 2005, published March 15, 2005 (PMID 15780846, doi:10.1016/j.biopsych.2004.12.006); Brunette 2025, published March 14, 2025 (PMID 38900958, doi:10.1093/schbul/sbae097, NCT01964404, 2025)); Vadhan 2017, published November 2017 (PMID 28803095, doi:10.1016/j.psychres.2017.07.070, PMID 37287664); Schwarcz 2009, published June 2009 (PMID 19440079, doi:10.1097/JCP.0b013e3181a6bc3b); McLoughlin 2014 (Cochrane), published October 14, 2014 (PMID 25314586, doi:10.1002/14651858.CD004837.pub3, PMID 18646115); Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged)); Freeman 2019, published December 2019 (PMID 31580839, doi:10.1016/j.neubiorev.2019.09.036); Hindley 2020, published April 2020 (PMID 32197092, doi:10.1016/S2215-0366(20)30074-2); Robinson 2023, published July 2023 (PMID 35321777, doi:10.1017/S0033291722000502); Solmi 2023, published August 30, 2023 (PMID 37648266, doi:10.1136/bmj-2022-072348); Schoeler 2016, published March 2016 (PMID 26777297, doi:10.1016/S2215-0366(15)00363-6); Kraan 2016, published March 2016 (PMID 26568030, doi:10.1017/S0033291715002329); Javed 2026, published February 9, 2026 (PMID 41664079, doi:10.1186/s12888-025-07382-2); D'Souza 2022 (WFSBP), published December 2022 (PMID 35315315, doi:10.1080/15622975.2022.2038797); Norlin Mølgaard 2026 (Danish guideline), published August 2026 (PMID 42482516, doi:10.1080/08039488.2026.2697960); Di Forti 2019, published May 2019 (PMID 30902669, doi:10.1016/S2215-0366(19)30048-3); Hjorthøj 2023, published November 2023 (PMID 37140715, doi:10.1017/S0033291723000880, PMID 34287621, the share of schizophrenia cases rose from about 2% in 1995 to 6–8% after 2010)); Young-Wolff 2026, published February 6, 2026 (PMID 41719031, doi:10.1001/jamahealthforum.2025.6839); Dubois 2024, published February 2024 (PMID 38330686, doi:10.1016/j.schres.2024.01.029)

AddictionUpdateOctober 28, 2026

On October 28, 2026, sources found for this page during the searches for other topics were processed. In the medical cannabis card study (Gilman 2022), the number of people was corrected: 269 people were randomly assigned to groups and 186 were analyzed; the daily survey analysis of the same trial (Tervo-Clemmens 2023) was added. The evidence description for CBD in cannabis addiction was lowered from 'weak–moderate' to 'weak,' so that it now matches the evidence label on the page (weak). Three small studies testing non-cannabinoid ADHD medicines for cannabis addiction in people who also have ADHD, and a caution note that blood pressure can rise in some people when cannabis is stopped suddenly, were added. A finding on cannabis use and quitting smoking in cancer patients was not added because its numbers could not be verified from the primary source. The conclusion and the evidence label did not change.

AddictionUpdateOctober 28, 2026

PubMed, Cochrane and ClinicalTrials.gov were searched again in October 2026, separately for each substance (3,814 records in PubMed and 985 on ClinicalTrials.gov; an independent audit search was also done). The scope was broadened, adding a tobacco (smoking) section and cannabinoid hyperemesis syndrome (harm information) to the page; tobacco was added to the title. 26 rows added: in cannabis addiction, 6 clinical studies and 4 short lab or inpatient studies with THC-containing or THC-like medicines (a mouth spray containing THC and CBD, synthetic THC, nabilone), 1 lab study with CBD alone and 1 small CBD study with results only in a registry; for opioids, 2 studies with CBD (one with results only in a registry) and 2 with synthetic THC; for crack cocaine, 1 CBD study; for alcohol, 1 lab study with THC-containing marijuana; for smoking, 2 small controlled studies with CBD; 1 controlled study measuring the risk of cannabis use disorder with THC-containing cannabis products; 5 systematic reviews and meta-analyses. Small lab studies repeating the same method, uncontrolled studies and reviews repeating the same question were not added to the table individually; studies on CBD's own addiction potential were cited with their sources in the text. Corrected: the statement that use was never measured in the opioid studies was updated in light of the 76-person study with results only in a registry; product information for two studies was added from the registry and protocol; registry numbers, secondary publications, correction notices and one company tie were added to existing rows; it was noted that in one alcohol study a drinking measure listed in the registry was not published; the conclusion and strength-of-evidence text for THC-containing products was rewritten to match the table; the search numbers were added to the evidence summary. The conclusion and the strength of evidence did not change.

Related studies: Allsop 2014, published March 2014 (PMID 24430917, doi:10.1001/jamapsychiatry.2013.3947, ANZCTR ACTRN12611000398909); Lintzeris 2019, published September 1, 2019 (PMID 31305874, doi:10.1001/jamainternmed.2019.1993, ANZCTR ACTRN12616000103460, PMID 32768992, PMID 35316689, mood, sleep and pain improved similarly in both groups), PMID 36209081, PMID 29776349, correction: JAMA Intern Med 2023, 183(12):1414, PMID 37812434, content could not be read)); Trigo 2018, published January 31, 2018 (PMID 29385147, doi:10.1371/journal.pone.0190768, NCT01747850, PMID 37692969, values within normal limits), PMID 27261670); Levin 2011, published July 1, 2011 (PMID 21310551, doi:10.1016/j.drugalcdep.2010.12.010, NCT00217971, PMID 24067260); Levin 2016, published February 1, 2016 (PMID 26711160, doi:10.1016/j.drugalcdep.2015.11.025, NCT01020019, PMID 34087745); Hill 2017, published December 2017 (PMID 28921814, doi:10.1111/ajad.12622, NCT01347762); Slagle 2026 (PP-01), published November 2026 (online September 9, 2026) (PMID 42717263, doi:10.1111/ajad.70202, NCT05494437, finished in August 2023, no results), NCT07644052, ongoing)); Haney 2013, published July 2013 (PMID 23443718, doi:10.1038/npp.2013.54, A study by the same center testing nabilone together with the sleep medicine zolpidem in the same laboratory relapse model was not given a separate row, its result points the same way: Herrmann 2016 (11 people, zolpidem + nabilone reduced withdrawal-related disruptions in mood, sleep and eating, and relapse to marijuana smoking, PMID 27085870); Haney 2016 (CBD), published July 2016 (PMID 26708108, doi:10.1038/npp.2015.367, NCT01844687, PMID 28088032); Schlienz 2018, published June 1, 2018 (PMID 29689485, doi:10.1016/j.drugalcdep.2018.02.022, NCT01394185, two other studies by teams that included the same researcher (Vandrey), measuring the effect of oral THC on withdrawal during cannabis-free periods with a dose comparison, were not given separate rows, their results point the same way (THC reduced withdrawal in a dose-dependent way): Budney 2007 (8 people, outpatient, PMID 16769180, inpatient, PMID 22921474); Herrmann 2019, published July 2019 (PMID 30378231, doi:10.1111/adb.12664, A study by the same center using the same method, with a different result (nabilone reduced relapse to smoking), is in a separate row: Haney 2013); NCT03102918 (McLean Hospital, registry results), published January 25, 2019 (registry results) (NCT03102918, 2019)); Bisaga 2015, published September 1, 2015 (PMID 26187456, doi:10.1016/j.drugalcdep.2015.05.013, NCT01024335); Lofwall 2016, published July 1, 2016 (PMID 27234658, doi:10.1016/j.drugalcdep.2016.05.002, PMID 26483357); Costa 2026 (opioids and pain), published October 2026 (online May 20, 2026) (PMID 42162267, doi:10.1038/s41386-026-02443-w, NCT04587791, PMID 41496743, NCT05076370, no marked sedation in the registry results)); NCT06206291 (Mount Sinai, registry results), published June 18, 2026 (registry results) (NCT06206291, 2026)); Meneses-Gaya 2021, published 2021 (PMID 33146345, doi:10.1590/1516-4446-2020-1416); Metrik 2026, published February 1, 2026 (PMID 41254853, doi:10.1176/appi.ajp.20250115, NCT02983773); Morgan 2013, published September 2013 (PMID 23685330, doi:10.1016/j.addbeh.2013.03.011); Hindocha 2018, published September 2018 (PMID 29714034, doi:10.1111/add.14243, Second publication of the same trial: Hindocha 2018b, PMID 29765102, impulsivity and memory)); Gilman 2022, published March 1, 2022 (PMID 35302633, doi:10.1001/jamanetworkopen.2022.2106, NCT03224468, PMID 36960460, PMID 36638745, 181 people, frequency of cannabis use increased over 12 weeks in those who got the card, but not in those waiting, according to the authors, this increase raises the risk of cannabis use disorder)); Zammit Dimech 2026, published July 17, 2026 (PMID 42466639, doi:10.1192/j.eurpsy.2026.12236, PROSPERO CRD420251151193); Redonnet 2025, published May 2025 (PMID 39947878, doi:10.1111/add.16745); Costa 2024, published January 2, 2024 (PMID 38225727, doi:10.1080/00952990.2023.2287406, PMID 33130527); Costa 2026 (alcohol review), published July 2026 (online February 27, 2026) (PMID 41760917, doi:10.1038/s41380-026-03523-5); Costa 2026 (tobacco review), published October 12, 2026 (PMID 42863773, doi:10.1016/j.neubiorev.2026.107032, PMID 41728311, PROSPERO CRD420250652724)

Skin ConditionsUpdateOctober 28, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were systematically searched; 11 studies were added: 4 randomized studies (the manufacturer's 200-person study in atopic dermatitis, nabilone for dialysis itch, seborrheic dermatitis in people with Parkinson's disease, THC+CBD oil in epidermolysis bullosa), a non-randomized comparison in systemic sclerosis ulcers, 2 systematic reviews (acne, skin wounds) and 4 uncontrolled studies (epidermolysis bullosa, scalp, hair loss). Two existing rows were reread and removed from the table: the itch reduction in the 2025 meta-analysis came from products containing no CBD or THC (PEA creams, hemp seed oil, synthetic research compounds), and the cream in the dialysis itch study was hemp seed oil pressed from the seeds and contained only trace amounts of CBD. The positive account, in two reviews, of a psoriasis study whose results could not be obtained (a CBD ointment applied to the skin) was added to the unverifiable points; product sources, company ties and publication dates were corrected. The conclusion and the strength of evidence did not change.

Related studies: BTX 1204 (Botanix) (NCT03824405, results entered in the registry on September 27, 2022)); Collister 2026 (DISCO-POT), published November 2026 (online June 23, 2026) (PMID 42889824, doi:10.1016/j.xkme.2026.101451, NCT05180968); Weber 2024, published March 11, 2024 (PMID 38466972, doi:10.2196/49965, NCT03582137, results in the registry)); Schräder 2026 (C4EB), published May 2026 (online February 25, 2026) (PMID 41742693, doi:10.1093/bjd/ljag072, Netherlands Trial Register NL9347, protocol: Schräder 2022, PMID 36508401); Spinella 2023, published January 2023 (PMID 36537770, doi:10.1097/01.ASW.0000891856.08360.61); Komane 2026, published June 9, 2026 (PMID 42357416, doi:10.3390/molecules31122017, PROSPERO CRD420251272093); Niyangoda 2024, published August 17, 2024 (PMID 39204426, doi:10.3390/pharmaceutics16081081, PROSPERO CRD42021255413); Mayrand 2026, published January 2026 (online October 17, 2025) (PMID 41105816, doi:10.1093/bjd/ljaf400, NCT05651607, September–November 2023, primary outcome itch at day 30, no results in the registry, the registry number could not be seen in the publication, and the link is based on matching institution, disease and design)); Vincenzi 2020, published November 2020 (PMID 33313051, doi:10.1159/000510896); Smith 2021, published April 2021 (PMID 37287996, doi:10.26828/cannabis/2021.01.003); Smith 2023, published 2023 (PMID 37305187, doi:10.4103/ijt.ijt_34_22, NCT04842383, the publication describes a single group of 31, the link could not be verified, no results in the registry))

DiabetesUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during the searches for other topics were read and added to the page. A US cohort examining cannabis use in adolescents and young adults with type 1 and type 2 diabetes (SEARCH; its full text could not be accessed in the first search) and a meta-analysis combining the effect of approved cannabinoids on appetite were added to the table. The weight-loss figures from the US prescribing information for the approved CBD medicine, a note that diabetic gastroparesis and cannabinoid hyperemesis syndrome can be confused, and the fact that there is no treatment study with a cannabis product in diabetic retinopathy were written into the text; the FAQ answer about weight was corrected based on these figures. The conclusion and the strength of evidence did not change.

Related studies: Spanagel and Bilbao 2021 (meta-analysis), published September 15, 2021 (online June 26, 2021) (PMID 34181977, doi:10.1016/j.neuropharm.2021.108680, PROSPERO CRD42021229932. Full text could not be read (paywalled, subscription required on Europe PMC), row based on the PubMed abstract. The same study also appears in the non-cancer appetite loss table); Roberts 2025 (SEARCH), published Winter 2025 (online September 4, 2024) (PMID 39959518, doi:10.2337/ds24-0019, PMC11825399 (read from the PMC article page, the Europe PMC full-text service and NCBI efetch did not return the article body). SEARCH 4: supported by NIH (NIDDK) and the US Centers for Disease Control, the authors reported no relevant conflicts of interest)

Blood PressureUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during the searches for other topics were read and added to the page. A 1982 case report was added to the warning about a drop in blood pressure on standing with THC-containing products: after smoking marijuana, blood pressure fell suddenly in 3 glaucoma patients, the picture resembled fainting, and the symptoms went away when they lay down. The information that blood pressure fell in some people in a 1977 study in which THC was given into a vein was not added, because it could not be verified in the study's own abstract. In the warning about blood pressure rising when stopping cannabis, it was stated clearly that 22.8 and 12.3 mmHg are the amount of the increase, not the blood pressure itself. The conclusion and strength of evidence did not change.

Blood PressureUpdateOctober 28, 2026

Information on blood pressure when stopping cannabis use was added to the "Who should be careful" section: in a 13-person study of daily users, blood pressure rose in some of them after stopping (Vandrey 2011), and in another study of 39 people there was no change (Bonnet 2016). The conclusion and strength of evidence did not change.

GlaucomaUpdateOctober 28, 2026

The October 2026 search added 16 sources: two controlled studies of THC eye drops in patients with glaucoma or ocular hypertension (one of them the 2-week study of a new drop that turns into THC in the eye in 56 patients, with results only on ClinicalTrials.gov); studies of smoked, intravenous and oral THC and of THC eye drops in healthy volunteers, and an RCT measuring optic nerve blood flow; a placebo-controlled study of oral THC in cancer patients receiving chemotherapy that also measured the pressure inside the eye; an uncontrolled study with nabilone; two systematic reviews and meta-analyses; the US National Academies report; the European Glaucoma Society guideline and the American Glaucoma Society position statement; and two observational studies on cannabis use and glaucoma risk. The Tomida 2006, Lindner 2026 and Merritt 1980 rows were corrected from the primary source; we added that the temporary pressure rise seen after 40 mg of CBD in the single human study was not significant in sources that re-analyzed this study against placebo; we noted in the 'fell in horses' sentence that the study had no placebo; and the THC findings and search counts were worked into the text. The finding and the strength of evidence did not change.

Related studies: Hommer 2020, published July 2020 (PMID 31977076, doi:10.1002/cpt.1797, NCT03907163, design, number of people and primary outcome, no registration number in the paper, no results in the registry). The same group's paper measuring retinal blood flow with the same design (24 healthy volunteers, 5 mg): Hommer 2021, PMID 33999707, whether it is from the same trial could not be verified); Merritt 1981, published August–September 1981 (PMID 6271841, doi:10.1002/j.1552-4604.1981.tb02626.x, The same group's second THC eye drop study in 8 patients: Merritt 1981, PMID 6114151, no abstract, could not be read, no difference from placebo according to the Passani 2020 review); Jay and Green 1983, published April 1983 (PMID 6301412, doi:10.1001/archopht.1983.01040010591012); Green and Roth 1982, published February 1982 (PMID 6279061, doi:10.1001/archopht.1982.01030030267006); Flom 1975, published January 1975 (PMID 1089090); Cooler and Gregg 1977, published August 1977 (PMID 329423, doi:10.1097/00007611-197708000-00016); Newell 1979, published January 1979 (PMID 530560, doi:10.1016/s0161-6420(79)35539-7); Dhivagaran 2026, published October 2026 (online August 5, 2026) (PMID 42069343, doi:10.1016/j.jcjo.2026.04.003); Bilbao 2022, published August 19, 2022 (PMID 35982439, doi:10.1186/s12916-022-02459-1); NASEM 2017 (US National Academies report), published January 2017 (PMID 28182367, doi:10.17226/24625, NCBI Bookshelf NBK423845, source of the glaucoma finding Whiting 2015, PMID 26103030); EGS 2025 (European Glaucoma Society guideline), published September 8, 2025 (PMID 41026937, doi:10.1136/bjophthalmol-2025-egsguidelines, Br J Ophthalmol 2025, 109(Suppl 1)); Jampel 2010 (American Glaucoma Society position), published February 2010 (PMID 20160576, doi:10.1097/IJG.0b013e3181d12e39, Text on the society's website (americanglaucomasociety.net/about/statements, read on October 28, 2026)); Katsimpris 2023 (Mendelian randomization), published November 10, 2023 (PMID 37949880, doi:10.1038/s41598-023-45872-z, Preprint: Research Square (Europe PMC PPR585420)); Lehrer 2022 (UK Biobank), published April 2022 (PMID 35093258, doi:10.1016/j.jfo.2021.12.012); NCT06144918 (SBI-100 eye drops, registry results), published January 14, 2026 (registry results) (NCT06144918, November 2023–February 2024, results in the registry, January 14, 2026, no publication in PubMed as of October 2026)); Levitt 1981, published August–September 1981 (PMID 6271814, doi:10.1002/j.1552-4604.1981.tb02583.x)

Tourette SyndromeUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during searches for other topics were read and added to the page. The supplementary table of the study examining national data on children receiving medical cannabis oil in Israel (Treves 2025) was read: most of the products given to children with Tourette syndrome were CBD-rich, but 96% of the bottles also contained THC; the row's product type was corrected to 'Contains THC' (the same publication is classified that way on the Autism page too), and the wording in the pure CBD section was clarified. The status of THC-containing medicines in Turkey was verified from TİTCK (Turkish Medicines and Medical Devices Agency) lists: they are not licensed in Turkey; the active substance of the mouth spray containing THC and CBD is on the list of medicines that can be imported from abroad with the agency's written approval, and dronabinol is not on this list. The conclusion and strength of evidence did not change.

ADHDUpdateOctober 28, 2026

October 2026 additional review: sources found for this page during searches for other topics were read and added to the page. Secondary ADHD findings from Tourette syndrome and tic disorder studies were added to the text: in the 97-adult controlled study, the larger reduction in tics in those with ADHD was not statistically significant, and the result for ADHD symptoms was not published; in the uncontrolled study with 10 adolescents, the drop in ADHD score was not significant. These studies are in the table of the Tourette Syndrome page; the number of controlled studies in ADHD (1) did not change. The conclusion and strength of evidence did not change.

Dravet SyndromeUpdateOctober 27, 2026

The reason for the difference between one table review's (Stockings 2018) 'low certainty' rating and the guide's 'strong' rating was added to the evidence summary: the review was based on two studies up to 2017, and later meta-analyses point in the same direction. The conclusion and the strength of evidence did not change.

Dravet SyndromeUpdateOctober 27, 2026

The Turkey line was corrected: the active ingredient of the approved CBD medicine (cannabidiol oral solution) is on the Foreign Active Ingredient List of TİTCK (the Turkish Medicines and Medical Devices Agency) and can be brought in from abroad with the agency's written approval; unsourced information about the SGK (Social Security Institution) list was removed. The conclusion and the strength of evidence did not change.

Lennox–Gastaut SyndromeUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane and ClinicalTrials.gov were systematically searched again (878 PubMed and 24 ClinicalTrials.gov records were reviewed; the findings were reread from primary sources in an independent check). Studies added: the Cochrane review of LGS medicines (Brigo 2021), a meta-analysis combining LGS only (Lattanzi 2018), a network meta-analysis comparing LGS treatments (Zhu 2025), a meta-analysis broken down by age and syndrome (de Oliveira 2026), a manufacturer analysis by clobazam use (Devinsky 2020), the three-year extension of the two studies (Patel 2021), two drug-level studies measuring the clobazam interaction (VanLandingham 2020, in patients; Morrison 2019, in healthy volunteers), everyday-practice studies from France, Germany and Korea (D'Onofrio 2020, Strzelczyk 2025, Koo 2020), use without clobazam (Nabbout 2023), adult LGS studies (Elbadri 2024, Aung 2026), unlicensed cannabis extracts (Press 2015) and a THC-containing product (Devinsky 2022). Added to the evidence summary: that the Cochrane review could not calculate the effect on all seizures because of insufficient data, that in patients not taking clobazam the reduction in the number of seizures was smaller and the response rate similar (the comparison was not made by chance assignment), and long-term liver data; for THC-containing products, the box and the strength of evidence were written for the first time ('Insufficient'). The two Lattanzi 2018 reviews in the table were distinguished by name. No third controlled treatment study was found. The conclusion and strength of evidence did not change.

Related studies: Brigo 2021 (Cochrane), published April 7, 2021 (PMID 33825230, doi:10.1002/14651858.CD003277.pub4, Update of the 2013 Cochrane review, PMID 35322410); Lattanzi 2018 (LGS meta-analysis), published October 2018 (PMID 30132269, doi:10.1007/s40263-018-0558-9); Devinsky 2020 (clobazam subgroups), published December 2020 (PMID 32592183, doi:10.1111/ane.13305, Gunning 2021, PMID 32969022, in LGS, the ratio of drop seizures vs. placebo was 0.70 in all patients (95% CI 0.62–0.80) and 0.56 with clobazam (0.47–0.67), OR for at least a halving 3.14 (2.04–4.81) and 3.48 (1.96–6.17), 3 of 7 authors are employees of the manufacturer, and 4 are consultants or investigators of the manufacturer); Zhu 2025 (network meta-analysis), published February 26, 2025 (PMID 40078280, doi:10.3389/fphar.2025.1522543); de Oliveira 2026 (meta-analysis by syndrome and age), published July 2026 (PMID 42185726, doi:10.1007/s40263-026-01301-z); Patel 2021 (GWPCARE5, LGS), published September 2021 (PMID 34287833, doi:10.1111/epi.17000, NCT02224573, separate final results for LGS in the registry, posted on February 3, 2022). Interim analysis: Thiele 2019, PMID 30740695, median 38 weeks, transaminase elevation 10.1% (29 of 37 patients were taking valproate), discontinuation due to side effects 9.6%); Morrison 2019 (clobazam, stiripentol and valproate interaction), published November 2019 (PMID 30791225, doi:10.1002/cpdd.665); D'Onofrio 2020 (France, slow dose increase), published August 12, 2020 (PMID 32903409, doi:10.3389/fneur.2020.00829); Nabbout 2023 (use without clobazam), published August 2023 (PMID 37331197, doi:10.1016/j.seizure.2023.05.003); Strzelczyk 2025 (Germany, real-world), published October 2025 (PMID 40650804, doi:10.1007/s40120-025-00788-w, Subanalysis of the same study in those using it together with clobazam: Strzelczyk 2025, PMID 40073826, 126 patients, 102 with LGS)); Elbadri 2024 (adult LGS, Birmingham), published August 2024 (PMID 38908033, doi:10.1016/j.yebeh.2024.109904); Aung 2026 (adult LGS, London), published October 2026 (PMID 42798297, doi:10.1111/ene.70760); Koo 2020 (Korea), published December 28, 2020 (PMID 33372424, doi:10.3346/jkms.2020.35.e427, Prospective study from the same center: Kim 2022, PMID 36062772, NCT04611438, 30 LGS + 11 Dravet): at least a halving in 26.8% at month 6, quality of life score did not change, PMID 36854341, the dose was started at 2.5–5 mg/kg/day and raised to 10 mg/kg/day over 2 weeks, and could be increased up to 20 if needed. The periods overlap (March–October 2019 and May 2019–December 2020), and the first author of Koo 2020 is also an author of Kim 2022, some patients are most likely shared); Press 2015 (unlicensed cannabis extracts), published April 2015 (PMID 25845492, doi:10.1016/j.yebeh.2015.02.043); Devinsky 2022 (THC-containing medical cannabis), published April 2022 (PMID 35267245, doi:10.1002/acn3.51537); VanLandingham 2020 (clobazam interaction, in patients), published October 2020 (PMID 32652616, doi:10.1002/jcph.1634, NCT02565108)

Lennox–Gastaut SyndromeUpdateOctober 27, 2026

The reason for the difference between the 'low certainty' rating of a review in the table (Stockings 2018) and the guide's 'Strong' rating was added to the evidence summary: the review was based on two studies up to 2017, and later meta-analyses point in the same direction. The conclusion and strength of evidence did not change.

Lennox–Gastaut SyndromeUpdateOctober 27, 2026

The Turkey row was corrected: the active substance of the approved CBD medicine (cannabidiol oral solution) is on the Foreign Active Substance List of TİTCK (Turkish Medicines and Medical Devices Agency) and can be imported from abroad with the agency's written approval; unsourced information about the SGK (Turkey's Social Security Institution) list was removed. The conclusion and strength of evidence did not change.

Tuberous SclerosisUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane, and ClinicalTrials.gov were systematically searched again (390 PubMed and 10 ClinicalTrials.gov records were reviewed). Studies added: Weinstock 2024 (34 patients in the expanded access program, follow-up of up to three years), Wray 2023 (everolimus interaction in healthy volunteers), Talwar 2023 and Tong 2024 (meta-analyses), Samanta 2022 (review), Cerulli Irelli 2025 (real-world data), Ebrahimi-Fakhari 2020 (everolimus and sirolimus levels), Barnett 2020 (tumor volume), and Shlomovitz 2021 (tuberous sclerosis cohort from Israel). Corrected: the definition of liver enzyme elevation in the main study and its rates by dose were added from the full text; it was noted that the 1% placebo rate in the US prescribing information is the combined figure from the studies of three diseases; the rate of discontinuation due to side effects was given using the tuberous sclerosis study's own data; it was noted that people taking everolimus or sirolimus were not included in the main study; the final results of the open-label extension on ClinicalTrials.gov were added; the absence of controlled studies with results for THC-containing products, and the strength of evidence for this area (insufficient), were stated for the first time. No second controlled study was found. The evidence level text was aligned with the badge ('Moderate' instead of 'Moderate–high'); the conclusion and the strength of evidence in the badge did not change.

Related studies: Weinstock 2024 (expanded access program), published October 2024 (PMID 39088193, doi:10.1002/epi4.13013, Hess 2016, PMID 27696387, 18 TSC patients (included among these 34 patients), at month 3, median reduction in weekly seizures 48.8%, ≥50% response 50%); Wray 2023 (everolimus interaction), published September 2023 (PMID 37132402, doi:10.1002/cpdd.1262); Talwar 2023 (meta-analysis), published January 2023 (PMID 36206805, doi:10.1016/j.expneurol.2022.114238); Tong 2024 (network meta-analysis), published March 2024 (PMID 38277848, doi:10.1016/j.yebeh.2024.109653); Samanta 2022 (scoping review), published March 2022 (PMID 35151190, doi:10.1016/j.yebeh.2022.108577, PMID 35581136, PMID 35500511); Cerulli Irelli 2025 (real-world, TSC subgroup), published July 2025 (PMID 40126049, doi:10.1111/epi.18378); Ebrahimi-Fakhari 2020 (mTOR inhibitor levels), published April 2020 (PMID 31924480, doi:10.1016/j.pediatrneurol.2019.11.017); Barnett 2020 (tumor volume), published July 2020 (PMID 32409220, doi:10.1016/j.jocn.2020.05.030); Shlomovitz 2021 (Israeli TSC cohort), published December 2021 (PMID 34491422, doi:10.1007/s00381-021-05348-9)

Tuberous SclerosisUpdateOctober 27, 2026

The European product information of the approved medicine was reread. Added: the difference from placebo in the share of patients whose seizures were at least halved was not statistically significant. The Turkey row was corrected: cannabidiol oral solution is on the Foreign Active Substance List of TİTCK (Turkish Medicines and Medical Devices Agency), and the unsourced information about the SGK (Social Security Institution) list was removed. The conclusion and the strength of evidence did not change.

Drug-Resistant EpilepsyUpdateOctober 27, 2026

The studies' sources were reread. Corrected: the dose of the CBD gel applied to the skin was written as a daily total (the journal's correction); the lower bound of seizure reduction in people taking placebo in the approved medicine's studies was corrected (13%); it was added that the between-group difference in the frontal lobe study was not statistically significant and that the groups were unbalanced at baseline; the denominator of the rate in the infantile spasms extension was corrected and the limitation of this measurement was added; the description of the prospective study with unregulated oils as the 'only' one was corrected; information on Turkey's list of medicines from abroad was added. The conclusion and the strength of evidence did not change.

AutismUpdateOctober 27, 2026

Where the 'Mixed results' label comes from was written into the plain summary and the evidence summary: in the controlled studies of pure CBD, the main outcomes were negative, and the positive findings came with products that also contain THC and mostly on secondary measures. The conclusion and the strength of evidence did not change.

AutismUpdateOctober 27, 2026

The year of a controlled study with pure CBD was corrected to the journal's print year (Trauner 2026), and a note was added that the clinician impression in this study was not a primary outcome; the authors' declaration of interests was added to the UK registry study. The conclusion and the strength of evidence did not change.

Chemotherapy NauseaUpdateOctober 27, 2026

PubMed, Cochrane and ClinicalTrials.gov were systematically searched again in October 2026 (1159 records on PubMed, 39 on ClinicalTrials.gov). 40 studies were added to the table: 30 controlled studies from 1975–1995 with dronabinol, nabilone and levonantradol; two recent studies, one comparing dronabinol with ondansetron and one adding it to palonosetron and dexamethasone (one of them with results only on ClinicalTrials.gov); a pilot study with a mouth spray containing THC and CBD; a recent study with pure CBD in advanced cancer; 5 systematic reviews, including two on children; and a records review of nabilone in children. Corrected: the product type of the Cochrane 2015 row (mixed, because it pooled several types of drugs) and its product description, and the publication date of Sukpiriyagul 2023; the rows now state that the two publications of the CannabisCINV trial are the same trial; the definition of this trial's complete response (no vomiting and no need for extra medicine) was corrected in the text; the statement in the text that “the older studies were not compared with today's anti-nausea medicines” was corrected, and the text now states that dronabinol is THC itself while nabilone is a THC-like medicine. The conclusion and the strength of evidence did not change.

Related studies: NCT00553059 (MD Anderson, registry results), published October 9, 2020 (registry results) (NCT00553059, October 9, 2020, no publication found on PubMed in October 2026)); Duran 2010, published November 2010 (PMID 21039759, doi:10.1111/j.1365-2125.2010.03743.x); Meiri 2007, published March 2007 (PMID 17355735, doi:10.1185/030079907x167525, NCT00642512, 64 people and 2003–2004 period, sponsor Solvay Pharmaceuticals, no results in the registry)); Sallan 1975, published October 16, 1975 (PMID 1099449, doi:10.1056/NEJM197510162931603); Herman 1979, published June 7, 1979 (PMID 375088, doi:10.1056/NEJM197906073002302); Chang 1979, published December 1979 (PMID 293141, doi:10.7326/0003-4819-91-6-819); Kluin-Neleman 1979, published October 1979 (PMID 516362); Frytak 1979, published December 1979 (PMID 517882, doi:10.7326/0003-4819-91-6-825); Ekert 1979 (children), published December 15, 1979 (PMID 231736); Sallan 1980, published January 17, 1980 (PMID 6985702, doi:10.1056/NEJM198001173020302); Colls 1980, published June 25, 1980 (PMID 6250106, Report of the same study as a letter: Colls 1980, PMID 6104004, Tramèr 2001 counted it twice); Steele 1980, published 1980 (PMID 6250699); Orr 1980, published November 1980 (PMID 6254456, doi:10.1001/archinte.140.11.1431, Second publication on the same 55 patients: Orr and McKernan 1981, PMID 6271846, Tramèr 2001 counted it twice); Chang 1981, published April 1, 1981 (PMID 6261926, doi:10.1002/1097-0142(19810401)47:7<1746::aid-cncr2820470704>3.0.co, 2-4); Neidhart 1981, published 1981 (PMID 6271838, doi:10.1002/j.1552-4604.1981.tb02571.x); Einhorn 1981, published 1981 (PMID 6271844, doi:10.1002/j.1552-4604.1981.tb02576.x); Ungerleider 1982, published August 15, 1982 (PMID 6284334, doi:10.1002/1097-0142(19820815)50:4<636::aid-cncr2820500404>3.0.co, 2-4, Patient preference analysis of the same study: Ungerleider 1985, PMID 3010696, 139 patients, preference was determined mainly by reduction in nausea), Tramèr 2001 counted it twice); George 1983, published 1983 (PMID 6311306); Ahmedzai 1983, published November 1983 (PMID 6315040, doi:10.1038/bjc.1983.247); Hutcheon 1983, published August 1983 (PMID 6352278, doi:10.1016/0277-5379(83)90032-9); Heim 1984, published 1984 (PMID 6467496, doi:10.1007/BF00257128); Sheidler 1984, published April 1984 (PMID 6373843, doi:10.1002/j.1552-4604.1984.tb01824.x); Stambaugh 1984, published 1984 (PMID 6392353, doi:10.1002/j.1552-4604.1984.tb02756.x); Niiranen 1985, published August 1985 (PMID 3002167, doi:10.1097/00000421-198508000-00013); Niederle 1986, published April 15, 1986 (PMID 3009962, doi:10.1007/BF01728184); Crawford 1986, published 1986 (PMID 3010011, doi:10.1007/BF02934575); Dalzell 1986 (children), published May 1986 (PMID 3013104, doi:10.1136/adc.61.5.502); Pomeroy 1986, published 1986 (PMID 3017596, doi:10.1007/BF00256701); Chan 1987 (children), published June 1987 (PMID 3035479); Cunningham 1988, published April 1988 (PMID 2838294, doi:10.1016/0277-5379(88)90300-8); McCabe 1988, published September 1988 (PMID 2847994, doi:10.1007/BF00175407); Lane 1991, published August 1991 (PMID 1652611, doi:10.1016/0885-3924(91)90026-z, Preliminary report of the same trial: Lane 1990, PMID 2173391, 19 patients, 17 evaluable), Tramèr 2001 counted it twice); Gilbert 1995, published December 1, 1995 (PMID 8635039, doi:10.1002/1097-0142(19951201)76:11<2330::aid-cncr2820761122>3.0.co, 2-f); Hardy 2023 (MedCan1-CBD), published March 1, 2023 (PMID 36409969, doi:10.1200/JCO.22.01632); Tramèr 2001, published July 7, 2001 (PMID 11440936, doi:10.1136/bmj.323.7303.16); Chow 2025, published February 14, 2025 (PMID 39953210, doi:10.1007/s00520-025-09251-w); Kemmner 2026, published August 2026 (PMID 40797063, doi:10.1007/s11764-025-01876-4); Phillips 2016 (Cochrane, children), published February 2, 2016 (PMID 26836199, doi:10.1002/14651858.CD007786.pub3, Previous version: Phillips 2010, PMID 20824866); Chhabra 2023, published November 15, 2023 (PMID 37635461, doi:10.1002/cncr.34920); Polito 2018 (children), published December 2018 (PMID 30051617, doi:10.1002/pbc.27374)

Appetite Loss in CancerUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were searched systematically; 13 studies were added: 6 randomized studies measuring appetite or taste perception in cancer patients (dronabinol, nabilone, pure CBD oil, an oil containing THC and CBD, a mouth spray containing THC and CBD, medical cannabis), 1 comparative observational study with nabilone, 1 open-label study with a THC-rich cannabis extract, 3 systematic reviews and 2 real-world studies. The product type of the nabilone study (Turcott 2018) was corrected; its result was completed to also show that, among the registered primary outcomes, there was no difference from placebo in appetite and weight. Group sizes, the weight result, limitations, the registry number or the second publication of the same trial were added to the Strasser 2006, Jatoi 2002 and Dominiak 2023 rows. It was added to the text that appetite was also measured in a pure CBD study in advanced cancer and was no different from placebo, and that in a study of cancer pain, appetite fared worse with a mouth spray containing THC and CBD than with placebo. Information that CBD may decrease appetite was added to the "Who should be careful" section (US product information for approved CBD; a review of 11 randomized studies, Pinto 2022). The conclusion and the strength of evidence did not change.

Related studies: Brisbois 2011, published September 2011 (PMID 21343383, doi:10.1093/annonc/mdq727, NCT00316563, no results in the registry)); Côté 2016, published April 2016 (PMID 26503964, doi:10.1177/0003489415612801); Hardy 2023 (MedCan1-CBD), published March 1, 2023 (PMID 36409969, doi:10.1200/JCO.22.01632, ANZCTR ACTRN12618001220257, protocol: Good 2019, PMID 31810437); Hardy 2025 (MedCan2), published July 24, 2025 (PMID 40705150, doi:10.1007/s00520-025-09763-5, ANZCTR ACTRN12619000037101, funding: Australian government (MRFF), the manufacturer provided the drug and placebo and had no role in the study); Zylla 2026 (CanPan), published January 9, 2026 (PMID 41510814, doi:10.1200/OP-25-01165, NCT06605430, 16-week dose-response analysis: Gupta 2026, PMID 42767994); Maida 2008, published March 2008 (PMID 18402303); Bar-Sela 2019, published 2019 (PMID 31595793, doi:10.1177/1534735419881498, NCT02359123); Simon 2022 (systematic review and meta-analysis), published February 2022 (PMID 34881518, doi:10.1002/jcsm.12861); Razmovski-Naumovski 2022 (systematic review), published June 2022 (PMID 35360989, doi:10.1177/02692163221083437); Creangă-Murariu 2025 (systematic review and meta-analysis), published September 2025 (PMID 40748522, doi:10.1007/s11912-025-01695-x, PROSPERO CRD42023479375); Aviram 2022, published May 2022 (PMID 35669038, doi:10.3389/fpain.2022.861037, 1-month study from the same research group: Aviram 2020, PMID 33265945, average weight did not change significantly)); Kasvis 2022 (Quebec Cannabis Registry), published October 2022 (PMID 35723729, doi:10.1007/s00520-022-07193-1); Johnson 2010, published February 2010 (PMID 19896326, doi:10.1016/j.jpainsymman.2009.06.008, NCT00674609, appetite result only in the registry))

Neuropathic PainUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane and ClinicalTrials.gov were searched systematically; 38 studies were added: 24 randomized studies of products containing THC (3 with results only in the trial registry: the drug maker’s diabetic neuropathy and spinal cord injury studies, and a study of dronabinol and inhaled cannabis in nerve-related low back pain; one with a THC-dominant oil applied to the skin in diabetic neuropathy), 1 randomized study with pure CBD cream applied to the skin, 3 with the THC-like drug nabilone, 1 with CBDV, a cannabinoid closely related to CBD, and 1 with a cannabis medicine of unreported composition, 5 systematic reviews including the 2026 Cochrane update, and 3 real-world studies. The 2018 numbers from the Cochrane review were replaced with those from the 2026 update; the conclusion and strength-of-evidence text for products containing THC were rewritten. The phrase 'a single study' for CBD applied to the skin was corrected: there is also a second study with a negative result. For two existing four-arm studies, the results of the THC arms were added; it was noted that the maximum dose of the mouth spray study (Nurmikko 2007) is contradictory in the registry; the product type of the 2018 Cochrane review became 'Multiple product types' and that of the CBD oil applied to the skin became 'CBD-rich extract, THC content unclear'. The conclusion and the strength of evidence did not change.

Related studies: Eibach 2021, published April 2021 (PMID 32770831, doi:10.1002/cpt.2016); Berman 2004, published December 2004 (PMID 15561385, doi:10.1016/j.pain.2004.09.013, NCT01606189, sponsor is the drug’s manufacturer)); Rog 2005, published September 27, 2005 (PMID 16186518, doi:10.1212/01.wnl.0000176753.45410.8b, NCT01604265, sponsor is the drug’s manufacturer). Open-label 2-year extension: Rog 2007, PMID 18035205, 28 completed 2 years, at least one drug-related side effect in 58)); Selvarajah 2010, published January 2010 (PMID 19808912, doi:10.2337/dc09-1029, NCT00238550, the publication gives no registration number)); NCT00710424 (manufacturer’s diabetic neuropathy study, registry results), published July 31, 2012 (registry results) (NCT00710424, results in the registry, July 31, 2012, sponsor is the drug’s manufacturer, and the registry states that publications must be submitted for company review, no publication found on PubMed in October 2026)); NCT01606202 (manufacturer’s spinal cord injury study, registry results), published September 28, 2012 (registry results) (NCT01606202, results in the registry, September 28, 2012, sponsor is the drug’s manufacturer, in October 2026, mentioned on PubMed only in a scoping review, PMID 33465022); Langford 2013, published April 2013 (PMID 23180178, doi:10.1007/s00415-012-6739-4, NCT00391079, sponsor is the drug’s manufacturer)); Serpell 2014, published August 2014 (PMID 24420962, doi:10.1002/j.1532-2149.2013.00445.x, NCT00710554, sponsor is the drug’s manufacturer)); Lynch 2014, published January 2014 (PMID 23742737, doi:10.1016/j.jpainsymman.2013.02.018, NCT00872144); Svendsen 2004, published July 31, 2004 (PMID 15258006, doi:10.1136/bmj.38149.566979.AE, Second publication in Danish: Svendsen 2005, PMID 16014264); Rintala 2010, published October 2010 (PMID 20855984, doi:10.1097/PHM.0b013e3181f1c4ec); Schimrigk 2017, published October 2017 (PMID 29073592, doi:10.1159/000481089, NCT00959218, no results in the registry)); Weizman 2018, published October 2, 2018 (PMID 30185448, doi:10.1212/WNL.0000000000006293, The same team’s 12-male-patient publication with the same design: Weizman 2024, PMID 38597988, THC 0.2 mg/kg, pain on a 0–100 scale from 53 to 35 with THC and from 52 to 44 with placebo, p < 0.05 vs. placebo). Whether the participants of the two publications are the same is not stated); Abrams 2007, published February 13, 2007 (PMID 17296917, doi:10.1212/01.wnl.0000253187.66183.9c, NCT00046722); Wilsey 2008, published June 2008 (PMID 18403272, doi:10.1016/j.jpain.2007.12.010, NCT00254761); Ellis 2009, published February 2009 (PMID 18688212, doi:10.1038/npp.2008.120, NCT00255580, PMID 22133305, during the cannabis week, plasma ghrelin and leptin rose, PYY fell, and insulin fell similarly to placebo)); Ware 2010, published October 5, 2010 (PMID 20805210, doi:10.1503/cmaj.091414, ISRCTN68314063); Wilsey 2013, published February 2013 (PMID 23237736, doi:10.1016/j.jpain.2012.10.009, NCT01037088); Wallace 2015, published July 2015 (PMID 25843054, doi:10.1016/j.jpain.2015.03.008, NCT00781001, secondary analysis: Wallace 2020, PMID 32565122); Wilsey 2016, published September 2016 (PMID 27286745, doi:10.1016/j.jpain.2016.05.010, NCT01555983, blood level analysis of the same trial: Wilsey 2016, PMID 27621666); Almog 2020, published September 2020 (PMID 32445190, doi:10.1002/ejp.1605); NCT02460692 (dronabinol and vaporized cannabis, registry results), published September 28, 2023 (registry results) (NCT02460692, results in the registry, September 28, 2023, no publication found on PubMed in October 2026)); Haney 2025, published October 2025 (PMID 40611810, doi:10.1089/can.2025.0028, NCT03782402, results in the registry)); Weiss 2025, published October 2025 (PMID 41211445, doi:10.3389/fonc.2025.1590168, NCT04398446, the authors declared no conflicts of interest); Kittithamvongs 2025, published February 1, 2025 (PMID 39115545, doi:10.1097/CORR.0000000000003221, Thai Clinical Trials Registry TCTR20191106004 (the registry page returned no content in October 2026), commentary: Hoffmeyer 2025, PMID 39330963); Frank 2008, published January 26, 2008 (PMID 18182416, doi:10.1136/bmj.39429.619653.80, ISRCTN15330757); Toth 2012, published October 2012 (PMID 22921260, doi:10.1016/j.pain.2012.06.024, A registration by the same institution with the same design, NCT01035281, 4 weeks single-blind nabilone, responders to the double-blind period, no results in the registry, the publication gives no registration number)); Turcotte 2015, published January 2015 (PMID 25288189, doi:10.1111/pme.12569, NCT00480181, no results in the registry, the drug’s marketer Bausch Health is a collaborator in the registry)); Ateş 2026 (Cochrane), published January 19, 2026 (PMID 41548880, doi:10.1002/14651858.CD012182.pub3, Previous version: Mücke 2018 (Cochrane, in this table)); McParland 2023 (meta-analysis), published April 2023 (PMID 36598058, doi:10.1136/rapm-2021-103431, PROSPERO CRD42017074255); Andreae 2015 (individual patient data meta-analysis), published December 2015 (PMID 26362106, doi:10.1016/j.jpain.2015.07.009, PROSPERO CRD42011001182, the 5 included studies: Abrams 2007, Ellis 2009, Ware 2010, Wilsey 2008 and Wilsey 2013 (all in this table), 4 of the 12 authors are investigators of these studies); Sherman 2026 (systematic review), published April 2026 (PMID 41714301, doi:10.1177/25785125261425444); Datta 2026 (systematic review), published September 2026 (PMID 42085369, doi:10.1080/15360288.2026.2664668); Hoggart 2015, published January 2015 (PMID 25270679, doi:10.1007/s00415-014-7502-9, NCT00713323, randomized withdrawal), results in the registry, sponsor is the drug’s manufacturer); Ueberall 2022 (German Pain e-Registry), published February 2022 (PMID 35140513, doi:10.2147/JPR.S340968, Other analyses of the same registry: Ueberall 2019, PMID 31190969, 497 with neuropathic pain, no control group), Ueberall 2022, PMID 34480564, 655 + 655)); Hjorthøj 2022 (Danish national registry), published February 2022 (PMID 34624164, doi:10.1002/ejp.1874, PMID 34743399); D'Andre 2024, published December 2024 (PMID 39016024, doi:10.1089/can.2023.0253, NCT05388058); Seevathee 2025, published 2025 (PMID 39720705, doi:10.1159/000542511, Thai Clinical Trials Registry TCTR20211220008)

Arthritis and OsteoarthritisUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were searched systematically; 12 studies were added: 3 randomized studies of products containing THC (a mouth spray containing THC and CBD in rheumatoid arthritis, two single-dose dronabinol studies in knee osteoarthritis), a study without placebo comparing three cannabinoid capsules, 5 reviews including Cochrane, and 3 observational studies. A non-peer-reviewed preprint and hemp seed oil studies were not included in the table; the reason is given in the evidence summary. Registration numbers were added to the five existing rows; the number of participants and the result of the knee osteoarthritis study (Pramhas 2023) were given in more detail, a funding note was added to two rows, and a strength-of-evidence note to the thumb-base study (Heineman 2022). The conclusion for products containing THC was rewritten, and the THC strength of evidence, which had been blank, was written for the first time ('Weak'). The conclusion and strength of evidence for CBD did not change.

Related studies: Blake 2006, published January 2006 (PMID 16282192, doi:10.1093/rheumatology/kei183, Letter: Wright 2006, PMID 16621924); Campbell 2023, published October 2023 (PMID 37202479, doi:10.1038/s41386-023-01597-1, NCT03098563, 2024, 58 people together with the Hamilton 2026 cohort, in the combined registry result, peak clinical pain (0–100) was 12.8 with dronabinol and 12.8 with placebo)); Hamilton 2026, published May 2026 (PMID 41481837, doi:10.1097/ALN.0000000000005925, NCT03098563, the results in the registry combine both cohorts)); Kruger 2026, published September 2026 (PMID 42140793, doi:10.1016/j.clinthera.2026.04.018); Richards 2012 (Cochrane), published January 18, 2012 (PMID 22258992, doi:10.1002/14651858.CD008921.pub2, The same team’s summary on inflammatory joint diseases (J Rheumatol Suppl 2012, PMID 22942326); Schulze-Schiappacasse 2022, published March 2022 (PMID 33859125, doi:10.1097/RHU.0000000000001745); Zintziovas 2026, published October 5, 2026 (PMID 42831900, doi:10.1007/s00296-026-06314-x); Dubois 2024, published July 2024 (PMID 38832841, doi:10.1080/03007995.2024.2363945, PROSPERO CRD42022354026); Abafita 2026, published July 27, 2026 (PMID 42515994, doi:10.1155/prm/3998239, PROSPERO CRD42024539941); Sajeev 2026 (UK Medical Cannabis Registry), published September 9, 2026 (PMID 42724108, doi:10.1177/11795441261480709, Earlier analysis of the same registry: Francis 2025, PMID 38976497, 12 months, the patients most likely overlap)); Francis 2024 (UK Medical Cannabis Registry), published June 2024 (PMID 38669060, doi:10.1080/15360288.2024.2340076); Schubert 2023, published April 2023 (PMID 37057257, doi:10.1177/20494637221147115)

AnxietyUpdateOctober 27, 2026

The official minutes of the decisions of the expert committee of India's drug regulator were found and added as a source; the information that in May 2026 the committee recommended approving the product on condition of a comparative phase 4 study was added. The conclusion and the strength of evidence did not change.

Panic AttacksUpdateOctober 27, 2026

PubMed, Cochrane and ClinicalTrials.gov were searched again systematically in October 2026 (665 records in PubMed, 113 in ClinicalTrials.gov). No new controlled study with cannabinoids in panic disorder was found. Added: the two most recent reviews gathering cannabinoid trials in mental health conditions, a meta-analysis on recreational cannabis use and panic disorder risk, and five observational studies; a separate conclusion text and evidence level for THC-containing products ('Insufficient': no treatment studies) were written for the first time. Corrected: the primary outcome numbers and protocol registration of the therapy study, the exploratory findings in the substudy, the registration number of the CO₂ study in healthy volunteers, the participant numbers in the registration and the publication, the fact that it was a lab study and its manufacturer support, and the description of the data the review relies on. The conclusion and the strength of evidence for CBD did not change.

Related studies: Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged)); Cooling 2026, published January 2026 (PMID 41343139, doi:10.1007/s40261-025-01501-3); Xue 2021, published February 2021 (PMID 32909828, doi:10.1177/0706743720952251); Zvolensky 2008, published October 2008 (PMID 18076905, doi:10.1016/j.jpsychires.2007.10.012); Cougle 2015, published July–August 2015 (PMID 26022838, doi:10.1016/j.jpsychires.2015.05.004); Feingold 2016, published March 2016 (PMID 26775742, doi:10.1016/j.euroneuro.2015.12.037); Bricker 2007, published 2007 (PMID 17096386, doi:10.1002/da.20248, Main trial: Roy-Byrne 2005, PMID 15753242, PMID 15993254); van Laar 2007, published August 2007 (PMID 17624975, doi:10.1111/j.1360-0443.2007.01875.x)

Social AnxietyUpdateOctober 27, 2026

The reason for the retraction of another CBD study by the author, done in cats, was verified from the journal's retraction notice, and its source was given. The conclusion and the strength of evidence did not change.

PTSDUpdateOctober 27, 2026

A small controlled study of nabilone, a THC-like synthetic medicine, in PTSD-related nightmares (Jetly 2015) was added; the conclusion for THC-containing products was split in two: overall symptoms and nightmares. The conclusion and the strength of evidence did not change.

InsomniaUpdateOctober 27, 2026

A new Cochrane review (October 2026) and a review pooling sleep lab studies were added; the insomnia finding of a meta-analysis pooling cannabinoid studies in mental health conditions (sleep time measured with an electronic device got longer) was added to the table. The effect of THC-containing products on measured sleep was separated by type of measurement: the drop in total sleep and REM is the finding of a single-dose pilot study. It was corrected that a CBD study in healthy young people did not show superiority over placebo on the overall sleep score. The conclusion and strength of evidence did not change.

DepressionUpdateOctober 27, 2026

PubMed, Cochrane and ClinicalTrials.gov were systematically searched again in October 2026 (3,707 records on PubMed, 730 on ClinicalTrials.gov; together with an independent second check). There is still no published controlled CBD study in patients diagnosed with depression. Added: placebo-controlled CBD studies measuring depression symptoms (brain tumors, advanced cancer, hand osteoarthritis and anxiety disorder), two small studies in which THC was tried in patients with depression in the 1970s, two studies testing randomized access to medical cannabis and stopping cannabis, three meta-analyses and three systematic reviews including the review by a Canadian mental health guideline group, medical cannabis registries, and large observational studies on cannabis use and depression risk. Studies asking the same question and covered by the reviews in the table were not added separately. Corrected: the dose of the student study (it was reported in the full text) and its outcome numbers, the depression outcome and company ties of the health care worker study, the number for the depression finding in the review, the table description of the animal studies review, and the table order. The conclusion and the strength of evidence did not change.

Related studies: Kotin 1973, published March 1973 (PMID 4569675, doi:10.1001/archpsyc.1973.01750330041007); Ablon 1974, published April 1974 (PMID 4592555, doi:10.1176/ajp.1974.131.4.448); Gilman 2022, published March 1, 2022 (PMID 35302633, doi:10.1001/jamanetworkopen.2022.2106, NCT03224468, PMID 36638745, 181 people, frequency of cannabis use increased in those who got the card, no improvement in depression symptoms at 12 weeks, the depression score was found to be very slightly lower on days when cannabis was used, but when limited to those whose use was confirmed by urine testing, this difference was not significant)); Belgers 2026, published October 2026 (online March 22, 2026) (PMID 42750778, doi:10.1093/nop/npag025, Netherlands Trial Register NL9623 (GRASS study)); Gundugurti 2024, published July 2024 (online May 18, 2024) (PMID 38797087, doi:10.1016/j.ajp.2024.104073, Clinical Trials Registry – India CTRI/2023/01/049110. Pharmacokinetic study that is part of the same trial: Gundugurti 2026, PMID 41613360, single dose of 300 mg, funded by Leiutis Pharmaceuticals). Research letter from the same team: Gundugurti 2026, PMID 42901095, new patient data could not be verified)); Vela 2022, published June 1, 2022 (PMID 34510141, doi:10.1097/j.pain.0000000000002466, NCT03693833); Hardy 2023 (MedCan1-CBD), published March 1, 2023 (PMID 36409969, doi:10.1200/JCO.22.01632, ANZCTR ACTRN12618001220257, protocol: Good 2019, PMID 31810437); Cooke 2021, published July 1, 2021 (PMID 34276449, doi:10.3389/fpsyt.2021.689957); Bharat 2026, published November 2026 (online August 11, 2026) (PMID 42617303, doi:10.1016/j.psychres.2026.117380); Stanciu 2021, published April 2021 (PMID 33530732, doi:10.1176/appi.ps.202000189); Churchill 2025, published February 12, 2025 (PMID 39936870, doi:10.1017/S0033291724003143); Burke 2024, published November 2024 (PMID 39620474, doi:10.1017/S0033291724002587); Sorkhou 2024, published April 9, 2024 (PMID 38655516, doi:10.3389/fpubh.2024.1346207); Lillywhite 2026 (UK Medical Cannabis Registry), published April 15, 2026 (online January 6, 2026) (PMID 41506388, doi:10.1016/j.jad.2025.121130, Earlier analysis of the same registry: Mangoo 2022, PMID 36573268, 6 months)); Specka 2024, published March 2024 (online January 11, 2024) (PMID 38211630, doi:10.1055/a-2215-6114); Martin 2021, published September 9, 2021 (PMID 34566726, doi:10.3389/fpsyt.2021.729800); Yana 2023, published February 2023 (PMID 36638694, doi:10.1016/j.psychres.2022.115047); Fontanella 2021, published April 1, 2021 (PMID 33464286, doi:10.1001/jamapediatrics.2020.5494); Young-Wolff 2026, published February 6, 2026 (PMID 41719031, doi:10.1001/jamahealthforum.2025.6839); Tourjman 2023 (CANMAT), published May 2023 (online June 16, 2022) (PMID 35711159, doi:10.1177/07067437221099769)

Bipolar DepressionUpdateOctober 27, 2026

PubMed, Cochrane and ClinicalTrials.gov were systematically searched again in October 2026 (1235 unique records in PubMed, 47 in ClinicalTrials.gov). No new controlled study of CBD in bipolar depression was found. Added: two small controlled studies from the 1970s in which THC was tested in patients with depression (some of them bipolar) (original articles could not be read, information from a review), a single-dose THC laboratory study in bipolar disorder, five systematic reviews or meta-analyses, one of them by Canada's CANMAT guideline group, an umbrella review, the clinical review cited as a source in the text, seven studies following the link between cannabis use and the course of bipolar disorder, and a large adolescent cohort; the conclusion text for THC-containing products was expanded accordingly. Corrected: the duration, dose increase and side effect details of the mania case report; the pilot study's reason for early termination (COVID-19 pandemic), number of participants, dose-increase schedule, product purity and the authors' conflict-of-interest statement (from the full text); the registry status, centers and dates of the ongoing phase 3 study; that the product tested in the anxiety pilot contains no THC according to the registry; the meta-analysis's online publication date and how many studies were pooled. For CBD, the conclusion and the strength of evidence did not change; for THC-containing products, the strength of evidence rose from 'Insufficient' to 'Very weak' (separate note).

Related studies: Kotin 1973, published March 1973 (PMID 4569675, doi:10.1001/archpsyc.1973.01750330041007); Ablon 1974, published April 1974 (PMID 4592555, doi:10.1176/ajp.1974.131.4.448); Miranda 2026, published October 2026 (online July 21, 2026) (PMID 42481733, doi:10.1038/s41386-026-02489-w, NCT04231643, bipolar patients and healthy volunteers, in the registry, a single oral dose of 5 mg dronabinol, 600 mg CBD or placebo, ended at 19 people for budget reasons, no results in the registry), the abstract gives no registry number, so the match could not be verified); Wilson 2026, published April 2026 (PMID 41856154, doi:10.1016/S2215-0366(26)00015-5, Correction: Lancet Psychiatry 2026, 13(8):e11, PMID 42302809, 2026, the axis of a figure and the study counts in the table were corrected, results unchanged)); Stanciu 2021, published April 2021 (PMID 33530732, doi:10.1176/appi.ps.202000189); Sorkhou 2024, published April 9, 2024 (PMID 38655516, doi:10.3389/fpubh.2024.1346207); Bartoli 2019, published August 2019 (PMID 31121199, doi:10.1016/j.neubiorev.2019.05.017); Solmi 2023, published August 30, 2023 (PMID 37648266, doi:10.1136/bmj-2022-072348); Kansagara 2026, published May 2026 (PMID 41801216, doi:10.1001/jamainternmed.2025.8215); Zorrilla 2015 (EMBLEM), published February 2015 (PMID 25430820, doi:10.1111/acps.12366, 12-month analysis of the same EMBLEM cohort: van Rossum 2009, PMID 19155808, PMID 20458676); Strakowski 2007, published January 2007 (PMID 17199055, doi:10.1001/archpsyc.64.1.57); Kim 2015 (BCOS), published July 2015 (PMID 26207128, doi:10.4306/pi.2015.12.3.349); Lagerberg 2021 (TOP), published May 4, 2021 (PMID 34017275, doi:10.3389/fpsyt.2021.656912, Earlier analysis of the same Oslo TOP cohort: Kvitland 2015, PMID 25651990, continued use associated with the mania score measured with the YMRS and functioning measured with the GAF)); Olivier 2025, published August 2025 (PMID 40221053, doi:10.1016/j.jad.2025.04.026); Smith 2025 (Prechter cohort), published February 2025 (PMID 39793525, doi:10.1016/j.psychres.2025.116357); Tyler 2015, published March 4, 2015 (PMID 25738578, doi:10.1371/journal.pone.0118916, Correction: PLoS One 2015, 10(3):e0123953, PMID 25822166); Young-Wolff 2026, published February 6, 2026 (PMID 41719031, doi:10.1001/jamahealthforum.2025.6839); Tourjman 2023 (CANMAT), published May 2023 (online June 16, 2022) (PMID 35711159, doi:10.1177/07067437221099769)

MigraineUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane and ClinicalTrials.gov were systematically searched; 6 studies were added: a small study in medication overuse headache comparing the synthetic THC-like medicine nabilone with ibuprofen (Pini 2012), a systematic review (Okusanya 2022) and four observational studies (Hooper 2026, Rhyne 2016, Baraldi 2022, Zhang 2021). The result of the group that inhaled THC alone, secondary outcomes, side effect rates and the number of people who treated attacks (73 of 92) were added to the acute migraine study's row, and the medication overuse headache finding was added to the review's row; 'single study' wording in the texts was corrected. Two small studies done in other conditions that tracked headache as a secondary outcome were not included in the table because they were not done in migraine patients. The conclusion and the strength of evidence did not change.

Related studies: Pini 2012, published November 2012 (PMID 23070400, doi:10.1007/s10194-012-0490-1); Okusanya 2022, published May 30, 2022 (PMID 35711271, doi:10.3389/fneur.2022.871187); Hooper 2026 (UK Medical Cannabis Registry), published April 2026 (PMID 41943196, doi:10.1002/brb3.71323, PMID 36722292, headache disorders, 97 patients, 6 months, improvement in HIT-6 and MIDAS, side effects in 17.5% of patients), the patients very likely overlap); Rhyne 2016, published May 2016 (PMID 26749285, doi:10.1002/phar.1673); Baraldi 2022, published February 1, 2022 (PMID 34347088, doi:10.1093/pm/pnab245); Zhang 2021, published September 2021 (PMID 34370866, doi:10.1111/head.14195, Preprint: Research Square, February 8, 2021, doi:10.21203/rs.3.rs-185874/v1, OR 5.99 in the preprint))

FibromyalgiaUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were systematically searched; 14 studies were added: 2 randomized studies with the THC-like medicine nabilone, 2 with THC-containing cannabis oils and 1 comparing three cannabinoid capsules, 1 non-randomized comparison with dronabinol, 4 systematic reviews including Cochrane, and 4 large real-world studies. Among existing rows, the daily dose and result numbers of the THC and CBD oil study were added from the full text, the number of people and side effects of the vaporized cannabis study were corrected, and registry numbers were added to four rows. The conclusion and the strength of evidence did not change.

Related studies: Skrabek 2008, published February 2008 (PMID 17974490, doi:10.1016/j.jpain.2007.09.002, NCT00272207, commentary: Staud and Koo 2008, PMID 18521112); Ware 2010, published February 2010 (PMID 20007734, doi:10.1213/ANE.0b013e3181c76f70, NCT00381199); Chaves 2020, published October 2020 (PMID 33118602, doi:10.1093/pm/pnaa303, ReBEC RBR-2f8mtn (registered after data collection, in March 2020)); Agbaria 2025, published November 6, 2025 (PMID 41199355, doi:10.1186/s42238-025-00348-x, NCT05644054, no results in registry)); Kruger 2026, published September 2026 (PMID 42140793, doi:10.1016/j.clinthera.2026.04.018); Walitt 2016 (Cochrane), published July 18, 2016 (PMID 27428009, doi:10.1002/14651858.CD011694.pub2); Giossi 2022, published December 2022 (PMID 36129666, doi:10.1007/s40122-022-00434-5); Duarte 2026, published March 2026 (PMID 42370077, doi:10.1016/j.ero.2026.01.016); Lam 2026, published April 2026 (PMID 42013320); Bettstetter 2024, published August 2024 (PMID 37289246, doi:10.1007/s00482-023-00727-4); Sagy 2019, published June 5, 2019 (PMID 31195754, doi:10.3390/jcm8060807); Giorgi 2020, published January–February 2020 (PMID 32116208); Sotoodeh 2023, published July 2023 (PMID 35876631, doi:10.1002/acr.24985); Varadpande 2026, published March 2026 (PMID 41343025, doi:10.1007/s10067-025-07846-6, Earlier fibromyalgia analyses of the same registry: Wang 2023, PMID 37199833, Sridharan 2025, PMID 39417761, products from a single manufacturer, PMID 39432707)

Crohn’s and Ulcerative ColitisUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were searched systematically; 10 studies were added: one randomized trial each with THC-rich marijuana cigarettes in Crohn’s disease and ulcerative colitis, 3 systematic reviews and meta-analyses, 2 studies following patients in real life, and 3 observational studies linking cannabis use to surgery, hospital admission and disease complications. In existing rows, the following were corrected: the dosing schedule, outcome numbers and adjusted analysis of the CBD/THC oil in Crohn’s disease; the serious event information and registry number of the pure CBD study; and the CBD amount, funding, registry information and product type of the ulcerative proctitis enema; citations for the Cochrane reviews were added. The conclusion and the strength of evidence did not change.

Related studies: Naftali 2013, published October 2013 (PMID 23648372, doi:10.1016/j.cgh.2013.04.034, NCT01040910, no results in the registry), PMID 24262941, PMID 24418092); Naftali 2021 (ulcerative colitis), published February 11, 2021 (PMID 33571293, doi:10.1371/journal.pone.0246871, NCT01040910, last updated December 2011, the design and results of this 32-person study are not in the registry), secondary analysis: Tartakover Matalon 2021, PMID 34531823); Doeve 2021, published October 2021 (PMID 32675631, doi:10.1097/MCG.0000000000001393); Kang 2025, published February 6, 2025 (PMID 39197096, doi:10.1093/ibd/izae158); Jugl 2026, published June 3, 2026 (PMID 42231518, doi:10.1186/s42238-026-00456-2, PROSPERO CRD42023411910); Gupta 2024, published December 2024 (PMID 39689344, doi:10.1080/17474124.2024.2443574, Earlier analysis of the same registry: Dalavaye 2023, PMID 36562418, 3 months, overlapping sample)); Fliss Isakov 2023, published December 26, 2023 (PMID 38201908, doi:10.3390/nu16010078); Storr 2014, published March 2014 (PMID 24407485, doi:10.1097/01.MIB.0000440982.79036.d6); Glickman 2024, published July 3, 2024 (PMID 37580878, doi:10.1093/ibd/izad151, PMID 37580879, PMID 37738592, PMID 37738640, PMID 39241176, PMID 39361966); Desai 2019, published June 2019 (PMID 31355219, doi:10.21037/atm.2019.04.63, Separate analyses of the same database with overlapping years: Mbachi 2019, Crohn’s (Dig Dis Sci, PMID 30825109, 2012–2014, PMID 31388856, PMID 31393356, PMC6708902, 2010–2014, PMID 31464963)

MS SpasticityUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane, and ClinicalTrials.gov were systematically searched; 25 studies were added: 19 randomized studies with THC-containing products (mouth spray containing THC and CBD, oral cannabis extract, synthetic THC, smoked marijuana) (three with results only in the ClinicalTrials.gov registry), 1 small crossover study in which a CBD-rich extract was also tested, 2 systematic reviews, and 3 real-world or safety registries. The product type of the Cochrane 2022 review was corrected to 'Multiple product types' (it also includes a nabilone study), and its conclusion was completed with the very small difference in doctor-measured muscle stiffness; in the row for the Danish study, the result for the pure CBD group is now given first. The dosing schedule, warnings, and drug interactions of the approved THC:CBD spray were added from the product information. There are still only two small randomized studies with pure CBD. The conclusion and the strength of evidence did not change.

Related studies: Wade 2003, published February 2003 (PMID 12617376, doi:10.1191/0269215503cr581oa); Markovà 2019 (SAVANT), published February 2019 (PMID 29792372, doi:10.1080/00207454.2018.1481066, EudraCT 2015-004451-40, PMID 32065006, PMID 37209500); Notcutt 2012, published February 2012 (PMID 21878454, doi:10.1177/1352458511419700, NCT00702468); Collin 2007, published March 2007 (PMID 17355549, doi:10.1111/j.1468-1331.2006.01639.x, NCT00711646, PMID 22878432, NCT01606137); Collin 2010, published June 2010 (PMID 20307378, doi:10.1179/016164109X12590518685660, NCT01599234); Wade 2004, published August 2004 (PMID 15327042, doi:10.1191/1352458504ms1082oa, NCT01610700, PMID 17086911, NCT01610687); NCT04203498 (RELEASE MSS3, registry results), published May 8, 2024 (registry results) (NCT04203498, EudraCT 2019-002623-14, results in the registry, May 8, 2024, no publication found in PubMed as of October 2026)); NCT04984278 (RELEASE MSS5, registry results), published February 5, 2024 (registry results) (NCT04984278, EudraCT 2020-003271-18, results in the registry, February 5, 2024, no publication found in PubMed as of October 2026)); Vachová 2013, published 2013 (doi:10.4172/jmso.1000122, NCT01964547, results in the registry, May 2, 2014), article: J Mult Scler (Foster City) 2013, 1(2)); Leocani 2015, published November 2015 (PMID 26289497, doi:10.1007/s00415-015-7878-1, NCT01538225); Aragona 2009, published 2009 (PMID 18978501, doi:10.1097/WNF.0B013E3181633497, PMID 18603457, pain reflex) and Tomassini 2014 (J Neurosci Rehabil, neurophysiology, not in PubMed)); De Blasiis 2021, published June 2021 (PMID 33862313, doi:10.1016/j.msard.2021.102805); Zajicek 2003 (CAMS), published November 8, 2003 (PMID 14615106, doi:10.1016/S0140-6736(03)14738-1, PMID 16291891, PMID 16552618); Zajicek 2012 (MUSEC), published November 2012 (PMID 22791906, doi:10.1136/jnnp-2012-302468, NCT00552604, Germany)); Vaney 2004, published August 2004 (PMID 15327040, doi:10.1191/1352458504ms1048oa); Killestein 2002, published May 14, 2002 (PMID 12011290, doi:10.1212/wnl.58.9.1404, Immune system publication from the same study: Killestein 2003, J Neuroimmunol); van Amerongen 2018, published September 2018 (PMID 28189366, doi:10.1016/j.clinthera.2017.01.016, EudraCT 2010-022033-28); Ungerleider 1987, published 1987 (PMID 2831701, doi:10.1300/j251v07n01_04); Corey-Bloom 2012, published July 10, 2012 (PMID 22586334, doi:10.1503/cmaj.110837); NCT00682929 (UC Davis, registry results), published May 18, 2018 (registry results) (NCT00682929, May 18, 2018, no publication found in PubMed as of October 2026)); Hamm-Buiar 2026, published October 2026 (PMID 42543771, doi:10.1002/bcp.70719, PROSPERO CRD42024557313, search December 2, 2025); Torres-Moreno 2018, published October 5, 2018 (PMID 30646241, doi:10.1001/jamanetworkopen.2018.3485, PROSPERO CRD42014015391, search up to July 2016); Patti 2016 (Italian AIFA registry), published September 2016 (PMID 27160523, doi:10.1136/jnnp-2015-312591, PMID 28763462, discontinuation), PMID 32335779, PMID 32661083, 18 months, 1, 845 patients), PMID 35590453); Flachenecker 2014 (MOVE 2), published 2014 (PMID 24525548, doi:10.1159/000357427, 12-month extension: Flachenecker 2014, PMID 24943098); Etges 2016 (manufacturer safety registry), published November 2016 (PMID 27956834, doi:10.2147/TCRM.S115014)

MS SpasticityUpdateOctober 27, 2026

A 3-year controlled study (CUPID) showing that synthetic THC did not slow disease progression in progressive MS was added; the statement 'higher doses have not been tested' was limited to controlled parallel studies. The conclusion and the strength of evidence did not change. The Turkey question now notes that the active substance of the mouth spray containing THC and CBD is on the Foreign Active Substance List of TİTCK (Turkish Medicines and Medical Devices Agency).

Parkinson’s DiseaseUpdateOctober 27, 2026

Two small controlled studies with the THC-like synthetic drug nabilone were added; the statement “all controlled studies are negative” was limited to CBD-containing products. For CBD, the conclusion and the strength of evidence did not change.

SchizophreniaUpdateOctober 27, 2026

The medicine maker's 12-week study, with results only in the study registry and no difference from placebo, was added; the number of people and outcome measure of a meta-analysis were corrected; the phrase 'well-designed studies' became 'controlled studies'. The conclusion and the strength of evidence did not change.

AddictionUpdateOctober 27, 2026

The Cochrane review (2025) of medicines for cannabis use disorder was added: the quit rate at the end of treatment with THC-containing medicines is no different from placebo. The wording on cocaine craving was refined; it was noted that use and relapse were not measured in the opioid studies. The conclusion and the strength of evidence did not change.

DiabetesUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane and ClinicalTrials.gov were searched systematically; 24 studies were added: 11 controlled studies (9 randomized; registry results of the manufacturer's unpublished CBD study in fatty liver, a spray containing CBD and THC in type 2 diabetes, a strip containing THCV and CBD and nabilone in obesity, CBD and CBD-rich cannabis extract in overweight people, and controlled studies of THC, nabilone and marijuana on blood sugar and insulin), 5 systematic reviews and 8 observational studies (cannabis use and type 2 diabetes, body weight, fatty liver, and ketoacidosis in type 1 diabetes). Group numbers and the primary outcome from the registry results were added to the type 2 diabetes study's row; the topic text was updated for the new studies; the conclusion and strength of evidence for THC-containing products were written for the first time ('Insufficient'). The conclusion and the strength of evidence for CBD did not change.

Related studies: Afshar 2022, published December 2022 (PMID 36945340, doi:10.5812/ijpr-132647, Iranian Registry of Clinical Trials IRCT20121021011192N10); NCT01284634 (manufacturer's fatty liver study, registry results), published January 20, 2014 (registry results) (NCT01284634, no publication found in PubMed in October 2026)); Smith 2025, published 2025 (PMID 39968488, doi:10.26828/cannabis/2024/000206, NCT05574049); Lopez 2020, published 2020 (PMID 32456572, doi:10.1080/19390211.2020.1765941, NCT04294706); Matheson 2025, published October 2025 (PMID 40353878, doi:10.1089/can.2025.0034, NCT04801641, April 9, 2026)); Reichenbach 2015, published October 1, 2015 (PMID 26283236, doi:10.1016/j.clinthera.2015.07.023, NCT01598207); Chia 2026, published May 1, 2026 (PMID 41869774, doi:10.1152/ajpendo.00391.2025, NCT01517100); Ewell 2021, published August 20, 2021 (PMID 34451914, doi:10.3390/ph14080817); Bryan 2026 (single-use study), published July 16, 2026 (PMID 42463843, doi:10.1038/s41598-026-62837-0, NCT04114903, August 6, 2026), methods publication Skrzynski 2026, PMID 41820717); Bryan 2025 (4-week use study), published September 2025 (PMID 40324550, doi:10.1016/j.amjmed.2025.05.002, NCT04114903, August 6, 2026)); Pinto and Martel 2022 (systematic review), published November 2022 (PMID 36180814, doi:10.1007/s40261-022-01205-y); Porr 2020 (rapid review), published August 17, 2020 (PMID 32807222, doi:10.1186/s13643-020-01411-9, PROSPERO CRD42019122829); Ravi 2018 (systematic review), published February 6, 2018 (PMID 29357394, doi:10.7326/M17-1548, PROSPERO CRD42016051297); Mousavi 2023 (meta-analysis), published November 2023 (PMID 37526051, doi:10.1002/ptr.7973); Quinapanta Castro 2025 (meta-analysis), published September 2025 (PMID 41141207, doi:10.7759/cureus.93183, PROSPERO CRD42025025065); Bancks 2015 (CARDIA), published December 2015 (PMID 26364621, doi:10.1007/s00125-015-3740-3); Danielsson 2016, published 2016 (PMID 27843955, doi:10.1155/2016/6278709); Baumeister 2021 (Mendelian randomization), published November 2021 (PMID 33580533, doi:10.1111/adb.13020); Alshaarawy 2019 (NESARC), published October 1, 2019 (PMID 30879064, doi:10.1093/ije/dyz044); Alayash 2021 (Mendelian randomization), published September 1, 2021 (PMID 34304124, doi:10.1016/j.drugalcdep.2021.108863); Wang 2020 (Mendelian randomization), published 2020 (PMID 32922442, doi:10.3389/fgene.2020.00949); Kinney 2020 (T1D Exchange), published January 2020 (PMID 31628116, doi:10.2337/dc19-0365); Abbotts 2022, published May 2022 (online May 21, 2022) (PMID 35631293, doi:10.3390/nu14102152, NCT04971837); Zhou 2026 (UK Biobank), published September 2026 (online April 17, 2026) (PMID 42115075, doi:10.1016/j.numecd.2026.104762)

Blood PressureUpdateOctober 27, 2026

In October 2026, PubMed, Cochrane, ClinicalTrials.gov and Europe PMC were searched systematically; 33 studies were added: 5 RCTs with CBD in healthy volunteers (in four, blood pressure and heart rate were no different from placebo; in one, blood pressure fell slightly), 9 studies with THC-containing products (heart rate, a drop in blood pressure on standing, heart rhythm, blood vessel function, angina, stroke patients taking blood pressure medicine; 8 of them controlled), 9 systematic reviews and meta-analyses, and 10 observational studies examining cannabis use and medical cannabis in relation to heart attack, stroke, heart rhythm problems, heart failure and high blood pressure. In the existing rows, the product, dose, registry number and funding of the high blood pressure studies were added; it was noted that both studies were carried out by the same research group, with the same company's patented product and with that company's funding, and that in the larger one the abstract does not make clear whether the drop was compared with placebo or with baseline. For the myocarditis study, the registered primary outcome, the funding of the heart inflammation studies, the authors' company ties and the side effects were added. The conclusion for THC-containing products was written for the first time (strength of evidence: 'Insufficient'). For pure CBD, the conclusion and strength of evidence did not change.

Related studies: Haney 2016, published July 2016 (PMID 26708108, doi:10.1038/npp.2015.367, NCT01844687, secondary analysis of the same trial: Babalonis 2017, PMID 28088032); Bell 2025, published December 20, 2025 (PMID 41515147, doi:10.3390/nu18010029, NCT06364254); Mastrofini 2024, published December 2024 (PMID 38904150, doi:10.1080/15502783.2024.2370430); Sellers 2013 (QT study), published July 2013 (PMID 27121791, doi:10.1002/cpdd.36, NCT01322139); Mathew 2003, published May 2003 (PMID 12873621, doi:10.1016/s0091-3057(03)00086-8); Laurentino 2026, published August 27, 2026 (online) (PMID 42660566, doi:10.1002/bcp.70793, Protocol: Fagundes 2025, PMID 41226928, the published analysis has three conditions), Brazilian registry RBR-3jsvtbr); Cheung 2024, published December 3, 2024 (PMID 39575727, doi:10.1161/JAHA.124.037731, NCT04693884, a second publication from the same trial: Cheung 2025, PMID 41115058); Elias 2026 (MARY-JANE), published July 30, 2026 (online) (PMID 42584385, doi:10.1016/j.jacc.2026.07.014, NCT06021613); Rosa 2022 (SativexStroke), published October 28, 2022 (PMID 36386386, doi:10.3389/fcvm.2022.990188, Main trial: Marinelli 2022, PMID 35812088); Crawford and Merritt 1979, published May 1979 (PMID 468444); Aronow 1975, published May 1975 (PMID 1126112, doi:10.1002/cpt1975175549, The same group's study comparing marijuana with placebo marijuana: Aronow 1974, NEJM, PMID 4599385, full text could not be read), psychological outcomes in 10 angina patients with the same design: Gottschalk 1977, PMID 870096, hemodynamics in coronary disease: Prakash 1975, PMID 1097149); Gonzalez 2026, published September 2026 (PMID 42665978, doi:10.14814/phy2.71076, Sleep and heart rate variability in the same participants: Gonzalez 2026, PMID 41692699); Roberts 2026, published June 19, 2026 (PMID 42321899, doi:10.1186/s42238-026-00463-3, A meta-analysis published in Brazil that the review cites (Candeloro 2025) could not be found in PubMed or Europe PMC); Sultan 2017, published February 24, 2017 (PMID 28286481, doi:10.3389/fphar.2017.00081); Sultan 2018, published January 31, 2018 (PMID 29385080, doi:10.3390/ph11010013, The PubMed title says "Δ8", the article's own title and text say Δ9-THC); Watanabe 2021, published 2021 (PMID 33952424, doi:10.1016/j.japh.2021.03.013); Storck 2025, published October 29, 2025 (PMID 40527600, doi:10.1136/heartjnl-2024-325429, PROSPERO CRD42023401401); Sebastian 2025, published March 2025 (PMID 39800612, doi:10.1016/j.disamonth.2024.101849, PROSPERO CRD42024530366); Ravi 2018 (systematic review), published February 6, 2018 (PMID 29357394, doi:10.7326/M17-1548, PROSPERO CRD42016051297); Chye 2026, published May 2026 (PMID 40472951, doi:10.1016/j.hrthm.2025.05.062, PROSPERO CRD42023428219); Ritson 2026, published July 2026 (PMID 41566428, doi:10.1177/17474930261418926, PROSPERO CRD420251053702); Abuhasira 2021, published April 2021 (PMID 33483174, doi:10.1016/j.ejim.2021.01.005, 15-person subgroup of the same cohort: Abuhasira 2022, PMID 36294974, THC/CBD ratios of the products)); Zongo 2021, published September 10, 2021 (PMID 34507536, doi:10.1186/s12872-021-02229-6, Heart failure in the same data source: Dubois 2026, PMID 41497552, 15:100120, 2014–2019 cohort)); Holt 2024, published February 7, 2024 (PMID 38200679, doi:10.1093/eurheartj/ehad834); Keyhani 2025, published August 12, 2025 (PMID 40686207, doi:10.1161/CIRCULATIONAHA.124.073193); Mittleman 2001, published June 12, 2001 (PMID 11401936, doi:10.1161/01.cir.103.23.2805, Long-term follow-up of the same cohort: Frost 2013, PMID 23351819, first follow-up analysis Mukamal 2008, PMID 18294478); Jeffers 2024, published March 5, 2024 (PMID 38415581, doi:10.1161/JAHA.123.030178); Corroon 2025 (CARDIA), published October 2025 (PMID 40785536, doi:10.1161/HYPERTENSIONAHA.125.25005, Cardiovascular events in the same cohort: Reis 2017, PMID 28207342); Haleem 2021, published September 2021 (PMID 33644920, doi:10.1111/dar.13266); Falkstedt 2017, published February 2017 (PMID 28028147, doi:10.1161/STROKEAHA.116.015565); Teraoka 2024, published April 2024 (PMID 38142832, doi:10.1016/j.hrthm.2023.12.008); Arout 2022, published January 2022 (PMID 34223660, doi:10.1111/bcp.14973); Spindle 2020, published June 1, 2020 (PMID 32247649, doi:10.1016/j.drugalcdep.2020.107937)

GlaucomaUpdateOctober 27, 2026

We clarified that the CBD in the human study was not pure but a CBD-dominant extract derived from cannabis; added that the horse study had no placebo; added four THC studies to the table; and corrected the year of one source. The finding and the strength of evidence did not change.

Dravet SyndromeUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: dose titration and participant details in the study table; drug interaction notes; the approved medicine's dosing schedule; the starting and titration summary; the "Who should be careful" list. Points that could not be verified from the full text went down from 4 items to 3. The conclusion and the strength of evidence did not change.

Lennox–Gastaut SyndromeUpdateOctober 21, 2026

The full texts of the studies were reread, and the information on the page was checked against its sources. Corrected: the dose increase details in the study table; the drug interaction notes; the approved medicine's dosing schedule; the starting and titration summary. The points that could not be verified from the full text went down from 3 items to 2. The conclusion and strength of evidence did not change.

Tuberous SclerosisUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: the dose titration information in the study table; drug interaction notes; the approved medicine's dosing schedule; the starting and titration summary; reported side effects. Points that could not be confirmed from the full text went down from 3 items to 1 item. The definition used to measure liver enzyme elevation was clarified. The conclusion and the strength of evidence did not change.

Drug-Resistant EpilepsyUpdateOctober 21, 2026

The full texts of the studies were reread, and the information on the page was checked against its sources. Corrected: participant numbers, side effects, results and duration in the study table; drug interaction notes; the approved medicine schedule; the evidence summary. Study added: GWPCARE7 pilot + extension (infantile spasms). Points that could not be verified from the full text went down from 6 items to 3. The year of one publication named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Related studies: GWPCARE7 pilot + extension (infantile spasms) (NCT02953548, NCT02954887)

AutismUpdateOctober 21, 2026

The full texts of the studies were re-read and the information on the page was checked against its sources. Corrected: side effect, dose, product and participant number information in the study table; drug interaction notes; the dose range in the studies; reported side effects. Points that could not be verified from full texts went down from 5 items to 3. A technical phrase ("failed to beat placebo") was replaced with a clearer one ("was not clearly different from placebo"). The year of 4 publications named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Chemotherapy NauseaUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: participant numbers, side-effect and dose information in the study table; drug interaction notes; evidence summary. Points that could not be verified from full texts went down from 4 items to 2. Our evidence assessment for THC-containing products and the recommendation grade of the ASCO 2024 guideline are now written separately. The conclusion and the strength of evidence did not change.

Cancer PainUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: duration, participant numbers and dose information in the study table; drug interaction notes; evidence summary. No points remain that could not be verified from the full text (previously 3 items). The conclusion and the strength of evidence did not change.

Appetite Loss in CancerUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: drug interaction notes. No points remain that could not be verified from the full text (previously 3 items). The conclusion and the strength of evidence did not change.

Sleep and Anxiety in CancerUpdateOctober 21, 2026

The full texts of the studies were reread, and the information on the page was checked against its sources. Corrected: drug interaction notes. Points that could not be verified from the full text went down from 4 items to 1. The conclusion and the strength of evidence did not change.

Cancer TreatmentUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: duration, dose, dose titration and side effect details in the study table; drug interaction notes; the "Who should be careful" list; the evidence summary; the finding for THC-containing products. Points that could not be verified from the full text went down from 4 items to 1. The conclusion and the strength of evidence did not change.

Pain After SurgeryUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: product, duration, registry number and study design details in the study table; the "Who should be careful" list. Points that could not be confirmed from the full text dropped from 4 items to 2. The year of 2 publications named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Neuropathic PainUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: side-effect and dose-titration information in the study table. Points that could not be verified from the full text went down from 2 items to 1. The conclusion and the strength of evidence did not change.

Arthritis and OsteoarthritisUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: dose, dose titration, side-effect and product information in the study table. Points that could not be verified from the full text went down from 3 items to 2. The conclusion and the strength of evidence did not change.

Chronic PainUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: participant numbers, doses, products and dose-increase details in the study table. Points that could not be verified from the full text went down from 2 items to 1 item. The year of 2 publications named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

CBD Cream (Topical)UpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: side effect, product and dose information in the study table. Points that could not be verified from the full text went down from 2 items to 1. The year of one publication named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

AnxietyUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: side effect, product, study design and dose information in the study table; drug interaction notes; the dose range in the studies; the starting and increase summary; the "Who should be careful" list; the reported side effects; the evidence summary. Points that could not be verified from the full text went down from 4 items to 3. The years of 7 publications named on the page were corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Panic AttacksUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: outcome, participant, duration and side effect details in the study table; drug interaction notes; the "Who should be careful" list; reported side effects; the evidence summary. Points that could not be verified from the full text went down from 3 items to 2. The year of 6 publications named on the page was corrected to the journal’s print year instead of the online publication year. The conclusion and strength of evidence did not change.

Social AnxietyUpdateOctober 21, 2026

The full texts of the studies were reread, and the information on the page was checked against its sources. Corrected: side effect, product, result and study design information in the study table; drug interaction notes; the "Who should be careful" list; reported side effects; evidence summary; the conclusion for THC-containing products. Points that could not be verified from the full text went down from 4 items to 3. The year of 8 publications named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

PTSDUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: product, number of participants, side effect and dose information in the study table; drug interaction notes; the dose range in the studies; the "Who should be careful" list; reported side effects; the evidence summary. Study added: Straud (NCT05132699, registry results). Points that could not be verified from the full text went from 3 items to 2. The year of 7 publications named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Related studies: Straud (NCT05132699, registry results) (NCT05132699, results October 10, 2024), protocol: Straud 2024, PMID 38404650)

InsomniaUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: duration, dose, side effect and product details in the study table; drug interaction notes; the dose range in the studies. No point remains that could not be verified from the full text (previously 2 items). The year of 7 publications named on the page was corrected to the journal’s print year instead of the online publication year. The conclusion and strength of evidence did not change.

DepressionUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: side effect and product information in the study table. The year of one publication named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Bipolar DepressionUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: duration and dose details in the study table. Points that could not be verified from the full text went down from 2 items to 1 item. The year of 3 publications named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

MigraineUpdateOctober 21, 2026

Technical terms in the For clinicians section were simplified; it was noted that the "CBD-dominant" group in one study used an inhaled product, not pure CBD oil. The year of one publication named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

FibromyalgiaUpdateOctober 21, 2026

A technical phrase ("failed to beat placebo") was replaced with a clearer one ("was not clearly different from placebo"). The year of a publication named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Crohn’s and Ulcerative ColitisUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against the sources. Corrected: the registry number, number of participants, side effect and dose information in the study table; the dose range in the studies. The conclusion and the strength of evidence did not change.

MS SpasticityUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: the registration number, number of participants, side effect, and dose information in the study table; the dose range in the studies. The conclusion and the strength of evidence did not change.

Parkinson’s DiseaseUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: duration, registration number and product information in the study table. Points that could not be verified from the full text went down from 2 items to 1 item. The conclusion and the strength of evidence did not change.

AddictionUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: participant numbers, side effects, product and registry number details in the study table. No points remain that could not be verified from the full text (previously 1 item). The year of a publication named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Skin ConditionsUpdateOctober 21, 2026

The full texts of the studies were reread and the information on the page was checked against its sources. Corrected: registry number, study design, participant numbers and side-effect information in the study table; evidence summary. No points remain that could not be verified from full texts (previously 1 item). The results of the BTX 1503 study were added from its ClinicalTrials.gov record. The year of 2 publications named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

DiabetesUpdateOctober 21, 2026

The year of a publication named on the page was corrected to the journal's print year instead of the online publication year. The conclusion and the strength of evidence did not change.

Blood PressureUpdateOctober 21, 2026

The year of a publication named on the page was corrected to the journal's print year instead of its online publication year. The conclusion and strength of evidence did not change.