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.
A single dose of psilocybin (0.25 mg/kg) produced rapid and sustained reductions in obsessive-compulsive disorder (OCD) symptoms among adults with treatment-resistant OCD. In a randomized, double-blind trial, 28 adults received either psilocybin or niacin (250 mg). At 48 hours, OCD severity scores dropped by about 10 points more in the psilocybin group than in the niacin group, a large effect. At one week, 69% of psilocybin participants achieved a clinically meaningful response, compared with none in the niacin group. Benefits lasted through 12 weeks. One serious adverse event occurred. Open-label psilocybin given later also reduced symptoms. The findings suggest psilocybin may offer a new treatment approach for treatment-resistant OCD, but larger confirmatory trials are needed.