Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

OBJECTIVE: To determine the relationships between psilocybin dose, psychedelic experiences, and therapeutic outcome in treatment-resistant depression. METHODS: For treatment-resistant depression, 233 participants received a single dose of 25, 10, or 1 mg of COMP360 psilocybin (a proprietary, pharmaceutical-grade synthesized psilocybin formulation, developed by the sponsor, Compass Pathfinder Ltd.) with psychological support. The resulting psychedelic experience (Five-Dimensional Altered States of Consciousness questionnaire [5D-ASC] and Emotional Breakthrough Inventory [EBI]) were measured. These proximal variables and outcome 3 weeks post-administration (change in Montgomery-Åsberg Depression Rating Scale [MADRS]) were explored using correlation analysis. RESULTS: The mean intensity of psychedelic effects was dose-related, but distributions of scores for different doses overlapped considerably. Depression response correlated with select aspects of the psychedelic experience overall and for individual doses. At the 25 mg dose, 5D-ASC dimensions Oceanic Boundlessness (Pearson correlation coefficient r = -0.508) and Visual Restructuralization (r = -0.516), and EBI (r = -0·637) were the variables with the strongest correlation to the Week 3 change from Baseline in MADRS score. LIMITATIONS: The existence of correlation does not establish causation and exploratory findings require further replication, preferably in larger independent samples. CONCLUSIONS: The intensity of psychedelic experience overlaps widely across doses and mitigates the risk of unblinding to dose. Correlations between psychedelic experience and outcome suggest specificity in psilocybin's mechanism of action. Quality and intensity of psychedelic experience may be a measure of pharmacodynamic effect and reveal an effective dose response phenomenon for single oral doses.

Original publication

DOI

10.1016/j.jad.2024.12.061

Type

Journal article

Journal

J Affect Disord

Publication Date

01/03/2025

Volume

372

Pages

523 - 532

Keywords

Dose-response, Psilocybin, Psychedelic, Psychedelic experience, Randomized-control trial, Treatment-resistant depression, Humans, Psilocybin, Hallucinogens, Male, Female, Depressive Disorder, Treatment-Resistant, Adult, Middle Aged, Treatment Outcome, Dose-Response Relationship, Drug, Psychiatric Status Rating Scales, Depressive Disorder, Major, Double-Blind Method