Overview
- Researchers synthesized 54 randomized trials from 1980 to May 2025 with 2,477 participants and found no evidence supporting cannabinoids for anxiety, PTSD or psychotic disorders, and no randomized trials assessing depression.
- Limited signals of benefit were reported for reducing cannabis withdrawal and use in cannabis-use disorder, decreasing tics in Tourette’s syndrome, increasing sleep time in insomnia and modestly reducing some autistic traits, though study quality was low.
- Across studies, cannabis users were more likely to experience adverse events, and cannabinoids increased cocaine cravings in people with cocaine-use disorder, prompting warnings that routine use could worsen outcomes or delay effective care.
- Prescribing has accelerated rapidly in countries such as Australia, where annual scripts rose from under 20,000 in 2020 to nearly 1 million, while private clinics in the UK and elsewhere are issuing high-THC products after brief video consultations.
- Study authors and medical bodies are urging stronger regulation and better trials, with Australia’s Therapeutic Goods Administration reviewing oversight and several larger studies underway to address evidence gaps.