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Jeremy Riva-Cambrin

Brain and Cognition Discovery Foundation, Toronto, ON, Canada.

3 papers in the library · 98 citations · publishing 2024-2025

Papers

Psilocybin-assisted psychotherapy for treatment resistant depression: A randomized clinical trial evaluating repeated doses of psilocybin.

Med (New York, N.Y.) March 8, 2024 Joshua D Rosenblat, Shakila Meshkat, Zoe Doyle et al. 97 citations

Psilocybin-assisted psychotherapy (PAP) is feasible for patients with complex, treatment-resistant depression, including those with bipolar II disorder and baseline suicidality. In a randomized trial with 30 adults, those receiving immediate PAP showed greater reductions in depression severity (MADRS) compared to a waitlist control, with a large effect size (Hedge's g = 1.07). Adverse events were transient and no serious adverse events occurred. Repeated doses over six months were associated with further improvement. The findings suggest PAP can be safely delivered to this population and warrants further study.

Comparing Antidepressant Effects of Psilocybin-Assisted Psychotherapy in Individuals That Were Unmedicated at Initial Screening Versus Individuals Discontinuing Medications for Study Participation: Comparaison des effets antidépresseurs de la psychothérapie assistée par la psilocybine (PAP) chez les personnes non médicamentées à la sélection initiale et les personnes ayant arrêté les médicaments pour participer à l’étude

The Canadian Journal of Psychiatry March 25, 2025 Noah Chisamore, Erica S Kaczmarek, Zoe Doyle et al. 1 citation

A single 25 mg dose of psilocybin combined with psychotherapy produced clinically significant reductions in depression, anxiety, and suicidality symptoms over two months in people with treatment-resistant depression. Among 27 participants, those who tapered off antidepressant medications before treatment (n = 18) and those not on antidepressants at screening (n = 9) showed comparable improvements, with no significant differences between groups on clinician-rated depression, self-reported depression, anxiety, or suicidality. The intensity of the psychedelic experience was also similar. These results suggest that tapering antidepressants before psilocybin-assisted psychotherapy may not diminish therapeutic benefits, though further research is needed.

Cognitive outcomes following psilocybin-assisted therapy in treatment-resistant depression: A post-hoc analysis of a randomized, waitlist-controlled trial

Progress in Neuro-Psychopharmacology and Biological Psychiatry November 22, 2025 Shakila Meshkat, Noah Chisamore, Zoe Doyle et al.

A single dose of psilocybin was linked to small, temporary gains in processing speed and executive function in people with treatment-resistant depression. These cognitive improvements seemed unrelated to mood changes but did not consistently surpass the improvements expected from simply retaking the tests. The findings underscore the need for larger, controlled studies to determine whether psilocybin genuinely enhances cognition or if the observed changes stem from practice effects or mood shifts.