The Efficacy and Tolerability of Psilocybin in Participants With Treatment-Resistant Depression: a Phase 2, Randomized Feasibility Study

The purpose of this study is to see if psilocybin, an investigational drug, is safe and well tolerated. Researchers also want to know if psilocybin can improve symptoms of depression. This study will see if psilocybin is safe and well tolerated by tracking changes in suicidal thoughts and behaviour, monitoring if any participants choose to stop participating in the study, and measuring any serious side effects, as well as how long they take to resolve. This study will also see if depression symptoms improve (or worsen) after psilocybin is administered. Additional information about participants' depressive symptoms and side effects will also be measured during the study. This randomized clinical trial will assess the feasibility, safety, and efficacy of single and repeat doses of psilocybin at point-of-care in persons with treatment-resistant depression as part of major depressive disorder or bipolar II disorder. The primary objective is to evaluate the feasibility of psilocybin in adults with treatment-resistant depression. The secondary objectives are to assess the efficacy and tolerability of psilocybin at point-of-care.