Grant: CIHR Fellowship

Suicide is a public health emergency but current interventions for treating suicidality remain inadequate. Novel fast-acting interventions are desperately needed. Psilocybin therapy is a re-emerging intervention that shows significant potential as a rapid and effective treatment for a range of mental health concerns characterized by heightened suicidality (e.g., major depressive disorder [MDD]). Preliminary research also suggests that psychedelic therapy may also safely and rapidly reduce suicidality. However, to date, all psychedelic therapy trials have excluded individuals with severe suicidality. Therefore, it remains unknown whether psilocybin therapy is safe and effective for individuals with severe suicidality. Furthermore, there is little understanding of how psilocybin therapy leads to reductions in suicidality. Therefore, this clinical trial will be the first to investigate the safety and efficacy of psilocybin therapy for individuals with severe suicidality. Using an open-label design, we will provide psilocybin therapy to 20 individuals with both chronic and severe suicidality and MDD. The treatment will involve administration of a single, large dose of psilocybin (25 mg) alongside psychotherapeutic treatment. We will examine changes in suicidality and depressive symptoms after treatment and at 6-month follow-up using clinical assessment and self-report. We will also examine changes in psychological (e.g., reductions in hopelessness) and neurobiological mechanisms that research suggests may underlie the effects of psilocybin therapy. We expect that the intervention will be safe and associated with large reductions in suicidality and depressive symptoms. These findings will help to explore the efficacy of psilocybin therapy as a novel rapid acting intervention for suicidality. Given the need for innovative interventions for suicidality, the present study is a critical step in developing and testing a promising intervention designed to reduce suicidality.