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Lindsay Billingsley

Squamish Nation

2 papers in the library · 2 citations · publishing 2025-2026

Papers

Group Retreat Psilocybin Therapy for People with Metastatic Cancer with Symptoms of Anxiety and Depression: Safety and Efficacy Outcomes of a Phase 1/2 Study

Psychedelic Medicine January 18, 2026 Anthony L. Back, Bonnie A. Mcgregor, Leslie Lazar Thorn et al. 1 citation

A group retreat model of psilocybin therapy for people with metastatic cancer and anxiety or depression was safe and well tolerated. Fifty-two participants attended a 3-day retreat with 25 mg psilocybin, supported by virtual and in-person sessions. No episodes of unattended distress occurred during the psilocybin sessions. Anxiety and depression symptoms, measured by the Hospital Anxiety and Depression Scale, decreased by an average of 7.3 points from baseline to 28 days after the retreat, a statistically significant reduction. The findings suggest that a group configuration of eight participants with four core facilitators can be safe for future studies in people with serious medical illness.

Group Retreat Psilocybin Therapy for People with Metastatic Cancer with Anxiety and Depression: A Rite of Passage Facilitation Model for a Phase 1/2 Study

Psychedelic Medicine December 23, 2025 Anthony L. Back, Bonnie A. Mcgregor, Lindsay Billingsley et al. 1 citation

A group facilitation model for psilocybin therapy, developed for an FDA-approved Phase 1 to 2 clinical trial, draws on anthropological studies of ritual, specifically rites of passage, to structure a secular retreat for people with metastatic cancer experiencing anxiety or depression. The model uses three phases: separation (preparation), liminal (psilocybin dosing session), and reincorporation (integration). Ritual functions psychologically to support emotional regulation and meaning-making, and communally to embed individual experience in shared intention and care. This is the first FDA-approved clinical trial of a secular ritual-based group facilitation model for psychedelic therapy with empirically demonstrated safety and efficacy outcomes.