Group Retreat Psilocybin Therapy for Healthcare Clinicians With Loss of Meaning in Their Work and Symptoms of Depression

This is a single-arm study that examines the feasibility of the group retreat format for clinicians and explores different 'doses' of preparation.

Population: Healthcare clinicians (physicians, nurses, nurse practitioners, physician assistants) aged 25-70 years currently in clinical practice with moderate or greater symptoms of depression (PHQ-9 ≥10) and loss of meaning during the past 5 years.

Study Design: Phase 2, non-randomized, sequential cohort dose-escalation study examining the optimal number of preparation sessions for group retreat psilocybin therapy. Three cohorts will receive different "doses" of preparation: Cohort 1 receives 7 total preparation sessions (6 virtual + 1 in-person), Cohort 2 receives 4 total preparation sessions (3 virtual + 1 in-person), and Cohort 3 receives 2 total preparation sessions (1 virtual + 1 in-person). Each cohort includes 3 retreats with 8 participants per retreat.

Sample Size: 72 participants total (24 per cohort, distributed across 3 retreats of 8 participants each) Study Duration: 18-24 months from enrollment of first participant to completion of final data analysis. Individual participant involvement spans approximately 8-10 months including 6-month post-retreat follow-up.

Primary Objectives: (1) Safety: Assess incidence and severity of challenging experiences and adverse events across preparation dose levels using the Challenging Experience Questionnaire (CEQ), adverse event monitoring, and psychiatric symptom scales (PHQ-9, GAD-7, C-SSRS). (2) Feasibility: Determine completion rates for preparation sessions at each dose level.

Secondary Objectives: (1) Mechanism Testing: Examine relationship between preparation dose, group cohesion, and challenging experiences. (2) Clinical Outcomes: Explore effects on depression and burnout for future power calculations. (3) Participant Preference: Assess participant-reported optimal preparation length.

Summary: Psilocybin therapy has demonstrated promising efficacy for symptoms of depression related to frontline work during the COVID pandemic for clinicians. The group retreat format offers potential advantages over individual treatment, including enhanced accessibility, reduced cost per participant, and potential therapeutic benefits from group cohesion and shared experience. However, a critical unanswered question concerns the optimal number of preparation sessions. A sequential dose-finding design is appropriate because: (1) the dose-response curve for preparation sessions in group format is unknown; (2) attrition/completion rate is a critical feasibility outcome, particularly for time-constrained healthcare clinicians; (3) the design allows protocol refinement between cohorts based on emerging data; (4) this approach is more scientifically honest about genuine uncertainty regarding optimal preparation dose than premature randomization; and (5) it seeks to establish a minimum effective dose of preparation for practical feasibility and future scalability.