This Phase III, randomized, double-blind, multicenter trial (n=240) aims to evaluate the efficacy, safety, and tolerability of psilocybin (5-25mg) in adults with Major Depressive Disorder (MDD).
Participants will be randomly assigned to receive a single oral dose of psilocybin 25 mg, psilocybin 5 mg, or an inactive placebo. The trial consists of a double-blind period followed by a 1-year follow-up period.
During the double-blind period, participants will undergo the “Set and Setting” Protocol for psychosocial support, including preparatory meetings and post-dose integration sessions. Outcome measures include changes in depressive symptoms, functional disability, health-related quality of life, and clinical global impression of disease severity.
After the initial period, participants will proceed to a 1-year follow-up period, during which long-term safety data will be collected, and eligible participants may be offered open-label psilocybin 25 mg re-administration under the “Set and Setting” Protocol.
The study is conducted at various locations across the United States and is sponsored by the Usona Institute. Recruitment started in March 2024, and the estimated primary completion is in April 2025, with the study completion estimated in April 2026.
See a discussion on the trial protocols here.
Trial Details
Trial Number
Sponsors & Collaborators
Usona InstituteThe Usona Institute was founded by Bill Linton and Malynn Utzinger. Currently, 18 people are associated with it. The institute is a non-profit that sponsors psilocybin research (and is funded by sponsors/philanthropists).