Cannabis-based medications have limited effectiveness in treating most mental health disorders, according to a comprehensive analysis published in The Lancet. The research, led by Jack Wilson of the University of Sydney, analyzed 54 clinical studies conducted between 1980 and May 2025, involving 2,477 participants, to evaluate cannabinoids as a primary treatment for mental disorders and substance use disorders.
The results indicate a lack of significant benefits for several conditions often cited in favor of medical cannabis: anxiety, psychotic disorders, PTSD, and opioid dependence. “When we look at the evidence as a whole, we simply do not see sufficient support for the routine use of these medications,” Wilson stated. This conclusion comes amid growing use of medical cannabis in countries such as the United States, Canada, and Australia, where patients frequently use it for anxiety, sleep disorders, or post-traumatic stress disorder.
Research Gaps
An important gap highlighted by the study is the complete absence of randomized clinical trials on the treatment of depression with cannabinoids—a major oversight given that depression is one of the most widespread mental health conditions. The analysis also shows that while the overall conclusions are cautious, there are limited potential benefits in certain situations: combinations of cannabidiol (CBD) and tetrahydrocannabinol (THC) may reduce withdrawal symptoms in cannabis users, reduce tics in Tourette syndrome, bring some improvements in autism spectrum disorders, and increase sleep duration in patients with insomnia. However, researchers emphasize that the quality of evidence for these effects is low.
Future Research Needs
The authors warn that the expansion of medical cannabis use is not matched by sufficient solid scientific evidence. They recommend larger clinical trials, more representative samples, and rigorous long-term assessments. Wilson concluded: “It is clear that more research is needed, especially for conditions where therapeutic options are limited.”
The study’s findings highlight a gap between the growing popularity of medical cannabis and available scientific evidence, suggesting that its use in psychiatry should be approached with caution until more conclusive data emerges.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://www.bursa.ro/study-limited-effectiveness-of-cannabis-based-medications-in-mental-health-83486854