Renske Erin Blom, PhD cand.

UMC Utrecht

Psilocybin in patients with treatment resistant depression:

first clinical experiences from a multicenter RCT



Psilocybin is a classical psychedelic and occurs naturally in mushroom-species. In the 1950’s psilocybin was synthesized and introduced as augmentation strategy in psychotherapy for several psychiatric conditions. Recent years have seen a renewed interest in the therapeutic use of psilocybin. Two recent studies show a fast and often persistent reduction in depressive symptoms [1], [2].


To assess the efficacy, optimal dosage and safety of psilocybin in improving depressive symptoms in a large international multicentre randomized controlled trial, with by COMPASS Pathways as sponsor.


In the RCT, 216 participants will be recruited in Europe, the USA and Canada before end of 2020. Participants are randomly assigned to double blind treatment with either 1mg, 10mg or 25mg of psilocybin. During the psilocybin-session, participants are guided by two trained therapists. Psilocybin-dosing is preceded by preparatory meetings with the therapist, integration sessions take place afterwards. The primary outcome is a reduction in depressive symptoms, measured with the MADRS.


The psilocybin-trial is currently running in the Netherlands in UMC Groningen, UMC Utrecht and LUMC Leiden. The first patients underwent psilocybin-treatment and new candidates are approved for inclusion.


Clinical experiences in treatment of the first RCT-participants will be discussed. The feasibility of treating this group of patients will be highlighted, as well as the subjective experience of patients undergoing this treatment. Finally, patients’ motivation for participation, experiences with patients after the psilocybin session and management of residual symptoms such as anxiety are discussed.


Renske Blom is a psychiatrist at GGZ Centraal/UMC Utrecht and a PHD-candidate. She is involved in the RCT: “the effect of psilocybin on treatment resistant depression”. She worked as the Sub-I in the trial for a year and is currently participating as a chaperone, guiding participants under the influence of psilocybin. She is most interested in the therapeutic effect of psychedelics. During her medicine-study, she studied the effect of MDMA on hyponatremia and was involved in the peer-education program (Unity), educating drug users about the effects of illicit drugs at dance-parties and festivals. She is currently still involved as a physician, advising drug users about the do’s and don’t of (illicit) drug use in combination with other drugs, medication or psychiatric disease.