A Study of Psilocybin for Major Depressive Disorder (MDD)

The purpose of this study is to evaluate the potential efficacy of a single 25 mg oral dose of psilocybin for MDD compared to the active placebo in otherwise medically-healthy participants, assessed as the difference between groups in changes in depressive symptoms from Baseline to Day 43 post-dose.

One hundred participants, ages 21 to 65, who meet the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for major depressive disorder (MDD) will be stratified by study site and randomized with a 1-to-1 allocation under double-blind conditions to receive a single 25 mg oral dose of psilocybin or a single 100 mg oral dose of niacin. Niacin will serve as an active placebo.

Topic Depression
Compound Placebo Psilocybin
Country United States of America
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Trial Details



Trial Number

Papers

Single-Dose Psilocybin Treatment for Major Depressive Disorder: A Randomized Clinical Trial
This Phase II trial (n=104) evaluated the effects of a single dose of psilocybin (25mg) vs niacin (100mg) placebo in adults with moderate or severe depression (MDD). Psilocybin treatment significantly reduced depression scores (MADRS & Sheehan Disability Scale) compared to niacin up to day 43. While there were no serious treatment-emergent adverse events, psilocybin was associated with a higher rate of overall and severe adverse events.

A review of psychedelics trials completed in depression, informed by European regulatory perspectives
This systematic review (s=8) analyses completed controlled trials of psychedelics for depression, including psilocybin, LSD, ayahuasca, and DMT, all in Phase II or I/II. It evaluates methodological patterns against the draft European Medicines Agency guideline revision, highlighting challenges such as unblinding, expectancy, and adverse event characterisation, while calling for larger studies to assess long-term efficacy and safety.

Measures Used

Montgomery-Asberg Depression Rating Scale
A ten-item diagnostic questionnaire used to measure the severity of depressive symptoms in patients with mood disorders.

Sheehan Disability Scale
The Sheehan Disability Scale (SDS) is a brief self-report measure developed to assess impairment in three inter-related domains; work/school, social life and family life.

Data attribution

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