Acceptability and safety of two sequential doses of psilocybin in bipolar II depression: protocol for an open-label single-arm feasibility study.
BMJ open July 13, 2026 Thomas D Meyer, Lauren N Vale, Maya Ibrahim et al.
A protocol describes an upcoming feasibility study testing psilocybin-assisted therapy in 10 outpatients with bipolar II disorder who have mild to moderate passive suicidal thoughts. Participants may receive two oral doses of 25 mg psilocybin about four weeks apart, combined with a structured mindfulness-based cognitive-behavioral therapy protocol. The study aims to assess the acceptability and safety of this approach, measuring changes in suicidality and depressive symptoms, and to gather preliminary data for a future randomized trial. Individuals with bipolar disorder and suicidality have typically been excluded from psilocybin trials due to safety concerns.