Skip to content

Benoit H. Mulsant

Centre for Addiction and Mental Health

5 papers in the library · 70 citations · publishing 2023-2025

Papers

Psilocybin for treatment-resistant depression without psychedelic effects: study protocol for a 4-week, double-blind, proof-of-concept randomised controlled trial

BJPsych Open July 1, 2023 Muhammad Ishrat Husain, Nicole Ledwos, Elise Fellows et al. 41 citations

A proof-of-concept randomized controlled trial will test whether combining the psychedelic psilocybin with risperidone, a drug that blocks the serotonin 2A receptor, can block psilocybin's psychedelic effects while preserving its antidepressant action in adults with treatment-resistant depression. Sixty participants will be randomly assigned to receive psilocybin plus risperidone, psilocybin alone, or placebo plus risperidone, all with 12 hours of manualized psychotherapy. Feasibility and tolerability will be assessed through recruitment, retention, and adverse events. If successful, this approach could make psilocybin therapy more acceptable and accessible by eliminating the need for a psychedelic experience and continuous monitoring.

Mapping psilocybin therapy: A systematic review of therapeutic frameworks, adaptations, and standardization across contemporary clinical trials

Journal of Affective Disorders July 18, 2025 Mary E. Kittur, Mingyao Liu, Brett D. M. Jones et al. 12 citations

Psilocybin therapy shows promise for rapid and lasting clinical benefits when paired with psychological support, but the field lacks standardized therapeutic guidelines. A systematic review of 22 recent trials across conditions like depression, substance use, and obsessive-compulsive disorders found broad consistency in the structure of therapy sessions—before, during, and after psilocybin administration. However, trials varied widely in therapeutic intensity, diagnostic adaptations, and use of evidence-based psychotherapies. Fewer than half reported standardization measures such as manualized procedures, specific training, or adherence monitoring. These gaps undermine replicability and generalizability, and until support protocols are clearly defined, mechanistic understanding and clinical adoption will remain limited.

Beyond Psilocybin: Reviewing the Therapeutic Potential of Other Serotonergic Psychedelics in Mental and Substance Use Disorders

Journal of Psychoactive Drugs August 24, 2023 Stanley Wong, An Yi Yu, Nicholas Fabiano et al. 11 citations

Interest in psychedelic therapies for mental and substance use disorders has grown, but evidence for non-psilocybin serotonergic psychedelics remains limited. A scoping review of mescaline, ibogaine, ayahuasca, DMT, and LSD identified 77 studies: 43 on LSD, 24 on ayahuasca, and 5 each on DMT, ibogaine, and mescaline. Reported benefits included improved mood, anxiety, insight, reduced substance use, better relationships, and fewer vegetative symptoms. Adverse effects were psychological, neurological, physical, and gastrointestinal; serious events like homicide and suicide appeared in LSD studies. The review concludes there is only low-level evidence supporting the safety and efficacy of these substances for mental and substance use disorders.

Effect of psilocybin therapy on suicidal ideation, attempts, and deaths in people with psychiatric diagnoses: a systematic review and meta-analysis

Therapeutic Advances in Psychopharmacology September 1, 2025 Stanley Wong, Gray Meckling, Nicholas Fabiano et al. 6 citations

A systematic review and meta-analysis of nine randomized controlled trials involving 593 adults with psychiatric diagnoses found that psilocybin therapy led to a small but significant decrease in suicidal ideation compared to control conditions. No studies reported suicide attempts or deaths. The analysis showed low heterogeneity and no publication bias, though two studies had a high risk of bias. Current evidence is limited by small sample sizes, insufficient follow-up data, and inadequate assessment of blinding.