Psilocybin for Treatment-Resistant OCD: A Randomised Controlled Trial
SSRN Electronic Journal January 1, 2026 Ben Kelemndi, Thomas Adams, Terence H. W. Ching et al. 1 citation
A single dose of psilocybin (0.25 mg/kg) produced rapid, clinically meaningful, and sustained reductions in obsessive-compulsive disorder (OCD) symptoms among adults with treatment-resistant OCD. In a randomized, double-blind, placebo-controlled trial, the psilocybin group showed a 9.76-point decrease on the A-YBOCS at 48 hours, compared to a 0.07-point increase in the niacin group. At one week, 69.2% of psilocybin participants achieved a response (≥35% symptom reduction) versus 0% of niacin participants. Benefits persisted through 12 weeks. One serious adverse event (suicidal ideation) occurred; no treatment-related deaths were reported.