Microdosing psilocybin for major depressive disorder: study protocol for a phase II double-blind placebo-controlled randomised partial crossover trial.

ABSTRACT:

Background

Major depressive disorder (MDD) is the leading cause of disability worldwide, affecting roughly 322 million people. Recently, doses of psilocybin have shown promise in treating mood disorders, sparking interest in other dosing practices. According to anecdotal reports and observational studies, microdosing psilocybin yields benefits to mental health; however, rigorously controlled trials have failed to produce compelling evidence for this.

Aims

To conduct a phase II, double-blind, placebo-controlled, randomised partial crossover trial to compare microdosing psilocybin to placebo for MDD, evaluating its safety, tolerability and preliminary antidepressant effects.

Method

Forty adults with MDD will be randomised to four doses of psilocybin (2 mg) or placebo (m

SUBMITTER: Beidas Z 

PROVIDER: S-EPMC12926881 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature