Efficacy of Psilocybin in OCD: a Double-Blind, Placebo-Controlled Study

Randomised, double-blind, active-placebo-controlled, single-dose study (psilocybin 0.25 mg/kg vs niacin 250 mg) in participants with moderate–severe OCD; participants are admitted inpatient for the dosing week.

Primary clinical assessments at 24 and 48 hours and at 1 week, 2 weeks, 1 month and 3 months; resting-state fMRI at baseline and 48 hours to examine fronto-striatal connectivity changes and their relation to symptom improvement.