A new review suggests psychedelic treatments, particularly psilocybin, may be more effective for obsessive compulsive disorder (OCD) than cannabis-based therapies.
The review, led by Dr Michael Van Ameringen of McMaster University and published in the Journal of Psychiatric Research, examined alternative treatments for OCD, a condition in which up to 60% of patients gain little relief from standard therapies such as SSRIs and exposure therapy. After analysing published studies, conference data and preliminary findings, researchers found stronger evidence supporting psychedelics than cannabinoids like THC and CBD.
Van Ameringen said the difference may lie in how the substances affect the brain. Cannabis activates CB1 receptors linked to anxiety and compulsions but appears to offer only short-term relief. Psilocybin, by contrast, reduces activity in the brain’s default mode network, which is associated with rumination and intrusive thoughts and is highly active in people with OCD.
Preliminary clinical trials, including work led by Yale psychologist Dr Terrence Ching, showed that a single dose of psilocybin reduced OCD symptoms more effectively than placebo. Researchers also noted that psychedelic trials typically include guided, therapeutic settings, unlike cannabis studies, which may influence outcomes.
The authors stressed that while findings are encouraging, further rigorous research is needed, and reducing global barriers to studying psychedelics remains essential.
