Methodological challenges in psychedelic drug trials: Efficacy and safety of psilocybin in treatment-resistant major depression (EPIsoDE) – Rationale and study design

This paper (2022) details the rationale and study design for an upcoming double-blind placebo-controlled trial (n=144) which will assess the safety and efficacy of using psilocybin in a cohort with treatment-resistant depression.


“Psychedelics such as psilocybin have recently gained remarkable interest in both the specialist literature and the lay press because studies suggest that these substances may have great therapeutic potential in various psychiatric disorders, including major depression. However, clinical trials with psychedelic drugs pose particular methodological challenges to researchers, some of which differ considerably from those with other psychotropic drugs. These include the problem of successful blinding, which can hardly be guaranteed in clinical trials with psychedelic substances and – directly related – the high risk of expectation bias and nocebo effects. Some of these challenges are being addressed in the given clinical trial on the efficacy and safety of psilocybin in treatment-resistant major depression. It is a phase II randomized, double-blind, active placebo-controlled parallel-group trial with 144 patients. The rationale, the study design, and the core features of the study are presented here. The trial (EPIsoDE trial; EudraCT number: 2019-003984-24; NCT04670081) is funded by the German Federal Ministry of Education and Research (BMBF 01EN2006 ​A/B).”

Authors: Lea J. Mertens, Michael Koslowski, Felix Betzler, Ricarda Evens, Maria Gilles, Andrea Jungaberle, Henrik Jungaberle, Tomislav Majic, Andreas Strohle, Max Wolff, Stefan Wellek & Gerhard Grunder

Study details

Compounds studied

Topics studied
Depression Treatment-Resistant Depression

Study characteristics
Placebo-Controlled Double-Blind

144 Humans


Authors associated with this publication with profiles on Blossom

Henrik Jungaberle
Dr. sc. hum. Henrik Jungaberle is the Director of the MIND Foundation and the CEO of OVID. He is a researcher, science entrepreneur, and author in public health, psychedelics, and psychotherapy. His focus is on human development from a lifespan and ecology perspective. He investigates integration and integrity in the use of psychoactive substances.

Gerhard Gründer
Gerhard Gründer is Professor of Psychiatry and Head of the Department for Molecular Neuroimaging at the Central Institute of Mental Health in Mannheim, Germany.


Institutes associated with this publication

MIND Foundation
The MIND Foundation is the European (Germany-based) non-profit that connects psychedelic research and education (mind academy). It is also the organization behind the INSIGHT conference.

Charité – Universitätsmedizin Berlin
The MIND Foundation recently announced a partnership with Charité – Universitätsmedizin Berlin.

OVID is a spin-off from the MIND Foundation, and will develop psychedelic therapy (infrastructure) in Germany/Europe. The spin-off was done so that this (LLC-like) entity is able to train therapists and host the (to date largest) psilocybin study for depression.

Linked Clinical Trial

Efficacy and Safety of Psilocybin in Treatment-Resistant Major Depression
The study aims to investigate the safety and efficacy of oral psilocybin administered under supportive conditions in treatment-resistant major depression (TRD).

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