Cannabis fails anxiety/PTSD tests
The largest meta‑analysis to date found no robust evidence that medicinal cannabis improves anxiety, depression, or PTSD and flagged increased risks for psychosis and addiction in some users. Authors warn cannabis may delay access to established, evidence‑based therapies. (sciencedaily.com)
Lancet Psychiatry published the full systematic review online March 16, 2026, under the title "The efficacy and safety of cannabinoids for the treatment of mental disorders and substance use disorders," with lead author Dr Jack Wilson of The Matilda Centre, University of Sydney. (businessofcannabis.com) The analysis pooled 54 randomized controlled trials conducted between 1980 and May 13, 2025, representing 2,477 trial participants across mental‑health and substance‑use indications. (theconversation.com) Pooled safety data reported higher odds of all‑cause adverse events with cannabinoids versus control (OR 1.75, 95% CI 1.25–2.46) and a calculated number‑needed‑to‑harm of 7, while finding no increase in odds of serious adverse events or study withdrawal. (sciencedirect.com) The paper documented an absence of randomized‑trial evidence for depression, and its pooled analyses showed no meaningful signal of benefit for conditions commonly cited in clinical practice such as anxiety and PTSD, while noting low‑quality, limited positive signals for insomnia, autism spectrum presentations, and tics/Tourette syndrome. (businessofcannabis.com) Lead author Dr Jack Wilson and coauthors highlighted risks including increased psychotic symptoms and the development of cannabis use disorder in some patients, and explicitly warned that prescribing cannabinoids could delay initiation of established evidence‑based psychological and pharmacological treatments. (medicalxpress.com) The authors placed their findings against rising medical use: roughly 27% of people aged 16–65 in the US and Canada report using cannabis for medical reasons and about half of those cite mental‑health reasons, alongside reports of more than one million prescription approvals and a tripling of cannabinoid medication sales in recent years. (sciencedaily.com)
