Retrospective Observational Study of Intensity Effects in Psychedelic-assisted Treatment

This retrospective observational study examines the effects of psychedelic-assisted psychotherapy (PAP) with lysergic acid diethylamide (LSD) or psilocybin in patients with treatment-resistant depressive, anxiety, or addictive disorders. Data will be analyzed from patients treated at the University Hospitals of Geneva between June 2020 and April 2025 who obtained individual authorizations from the Swiss Federal Office of Public Health for use of LSD or psilocybin under compassionate use criteria. The main objective is to assess the effects of psychedelic-assisted psychotherapy with LSD or psilocybin on changes in depressive symptoms, anxiety symptoms. Secondary objectives include evaluating the association between psychedelic session intensity and the administered dose of LSD or psilocybin, changes in depressive symptoms, anxiety symptoms, and problematic substance use, as well as their association with intensity effects. Additionally physiological effects during session will be assessed. All data are retrospectively collected from clinical records with prior patient consent. This study aims to generate evidence on the feasibility, safety, and therapeutic potential of PAP in real-world clinical practice.

NCT Number	NCT07164287
Lead Sponsor	University Hospital, Geneva
Conditions	Major Depressive Disorder (MDD), Anxiety Disorders, Substance Use Disorder (SUD), PTSD - Post Traumatic Stress Disorder
Enrollment	376 participants
Start Date	2020-06-01
Primary Completion	2025-04-30 (estimated)
Study Completion	2025-09-30 (estimated)
Updated on ClinicalTrials.gov	2025-10-02