Phase 1 trial suggests benefit of psilocybin in OCD treatment
The Brown University Psychopharmacology Update June 28, 2026 Peer reviewed DOI: 10.1002/pu.31474 via OpenAlex
Summary
High-dose psilocybin was more effective than both low-dose psilocybin and placebo in reducing symptoms of obsessive-compulsive disorder (OCD) in a Phase 1 trial involving 15 patients. The treatment was generally well-tolerated, with no serious adverse events reported.
Study at a glance
| Design | Phase 1 trial |
|---|---|
| Sample size | 15 |
| Population | patients with obsessive-compulsive disorder (OCD) |
| Key finding | Repeated high-dose administration of psilocybin was more effective than low-dose psilocybin or placebo in reducing OCD symptoms. |
Abstract
A Phase 1 trial comprising 15 patients has found that repeated high‐dose administration of psilocybin was more effective than low‐dose psilocybin or placebo in reducing symptoms of obsessive‐compulsive disorder (OCD). Psilocybin was generally well‐tolerated, with no reports of serious adverse events.