Long-term Observation of Participants With Mood Disorders

This prospective cohort follow-up (up to 1 year per participant) will re-contact former participants of Protocol 01-M-0254 to assess long-term depressive symptoms, suicide attempts, and ketamine utilisation via online surveys and telephone interviews.

Design comprises two remote phases: Phase 1 online surveys (~30 minutes) assessing current symptoms and treatments; Phase 2 telephone interviews (1–4 hours) for in-depth clinical and treatment history.

Primary endpoint is Beck Depression Inventory score; secondary endpoints include self-reported suicide attempts, self-reported ketamine use, and suicide mortality via National Death Index linkage.