Acceptability & Safety of Two Sequential Doses of Psilocybin in Bipolar Disorder II Depression and Suicidality

The purpose of the study is to assess the safety and acceptability of up to two sequential administrations of 25 mg psilocybin with additional therapeutic support in decreasing suicidality in patients with Bipolar Disorder (BD II) depression. This study aims to determine whether psilocybin paired with psychotherapy is a safe, feasible, and acceptable treatment for Bipolar II (BD II) depression, specifically, individuals experiencing suicidal ideation (without having an active plan or intention to act). The design is a non-randomized clinical trial, where patients will receive up to 2 doses of 25mg psilocybin in the context of psychological support informed by mindfulness-based CBT and typical elements of psychedelic treatments (e.g., preparation, intention setting, integration). The investigators will measure suicidality, depression, and acute experiences using validated questionnaires at multiple time points in the study. If this study shows psilocybin to be a feasible, acceptable, and safe treatment option, this would have huge implications for improving outcomes because highly effective treatment for suicidality in patients with Bipolar Disorder is still lacking.