A new review suggests psychedelic treatments, particularly psilocybin, may help reduce symptoms of obsessive-compulsive disorder (OCD), while cannabis shows little lasting benefit.
The review, led by Dr Michael Van Ameringen of McMaster University and published in the Journal of Psychiatric Research, examined evidence on alternative treatments for OCD, a condition in which up to 60% of patients do not respond adequately to standard therapies.
Researchers found stronger signals for psilocybin than for cannabinoids such as THC and CBD. Psilocybin appears to affect the brain’s default mode network, which is linked to rumination and intrusive thoughts common in OCD. Cannabis, while influencing anxiety-related pathways, did not show durable symptom improvement.
Preliminary clinical trials included in the review reported that single doses of psilocybin reduced OCD symptoms compared with placebo, with patients gaining insight into patterns of control and avoidance. Researchers noted that differences in study design may also play a role, as psychedelic trials often include structured therapeutic support.
The authors stressed that further controlled research is needed, particularly given the legal and practical barriers to studying psychedelic substances.
