Single-dose (10 mg) psilocybin reduces symptoms in adults with obsessive-compulsive disorder: A pharmacological challenge study

In this study, which was limited by a small sample size and the absence of randomisation, a 10 mg dose of oral psilocybin was found to be well-tolerated and potentially efficacious in patients with OCD. Psilocybin produced a rapid-onset, moderate to large effect on compulsive symptoms, which lasted up to one week after dosing. Future randomised placebo-controlled clinical trials investigating a longer course of multiple weekly doses of 10 mg psilocybin are indicated in OCD and in other obsessive-compulsive and related disorders characterised by compulsions.