Skip to main content
OpenTrials
Active, Not Recruiting

NCT Number: NCT07164287

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Major Depressive Disorder (MDD) Anxiety Disorders Chemically-Induced Disorders Combat Disorders Depressive Disorder Depressive Disorder, Major Mental Disorders Mood Disorders PTSD - Post Traumatic Stress Disorder Stress Disorders, Traumatic Substance Use Disorder (SUD) Substance-Related Disorders Trauma and Stressor Related Disorders

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Geneva University Hospital

Geneva, Switzerland

About this study

The overall project is a retrospective observational study evaluating the effects of psychedelic-assisted psychotherapy (PAP) with LSD or psilocybin in treatment-resistant depressive, anxiety, and addictive disorders. Data from 200 patients treated at Geneva University Hospitals will be included, with the primary aim of assessing relationships between psychedelic dose, subjective intensity of experience, and clinical outcomes.

Subset Analysis: Cardiovascular Outcomes In addition to the main objectives, a subset analysis will be conducted to evaluate cardiovascular effects of LSD and psilocybin. Routinely collected data from 30 patients with treatment-resistant depression or anxiety disorders will be included.

Population: 30 patients who underwent their first psychedelic session (LSD 100-200 µg or psilocybin 15-25 mg).

Measurements: Heart rate and self-rated anxiety (visual analogue scale) recorded at seven time points between 30 and 300 minutes post-administration on the treatment day.

A further subset analysis investigated the role of early maladaptive schemas (EMS) in psychedelic-assisted psychotherapy.

Populations: 192 patients who routinely completed the Young Schema Questionnaire - Rasch version (YSQ-R) before treatment were included; of these, 97 initiated PAP with LSD or psilocybin and 74 contributed longitudinal outcomes.

Measurements: Baseline EMS profiles (YSQ-R) measured at Baseline (screening or preparation visit, before first psychedelic session), immediately after each psychedelic session (sessions 1-3, up to 9 months) and 1 month after each psychedelic session (sessions 1-3, up to 12 months after baseline).

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients treated in the compassionate PAP program at Geneva University Hospitals between June 2020 and April 2025.
  • Diagnosis of depressive, anxiety, or addictive disorder resistant to standard treatments.
  • General consent for use of routinely collected clinical data.
  • Federal Office of Public Health authorization for PAP.

Exclusion criteria

  • psychotic disorder
  • bipolar disorder
  • high suicidal risk
  • severe cardiovascular disease
  • severe liver disease
  • neurological disease of the central nervous system
  • pregnancy
  • breastfeeding

Treatment and study plan

Lysergic Acid Diethylamide (LSD) or psilocybin

Drug

Psychedelic-assisted psychotherapy with LSD or psilocybin as a part of a clinical routine in our department

Primary outcomes

  1. Self-reported depressive symptoms (BDI-II)

    Time frame: Baseline and 1 month after each psychedelic treatment session (sessions 1-3, up to 12 months)

    Beck Depression Inventory-II, total scores ranging from 0 to 63, higher scores indicating higher depressive symptoms

  2. Self-reported symptoms of anxiety (STAI)

    Time frame: Baseline and 1 month after each psychedelic treatment session (sessions 1-3, up to 12 months)

    State-Trait Anxiety Inventory, total scores ranging from 20 to 80, higher scores indicating higher anxiety

Secondary outcomes

  1. Self-reported intensity of mystical experience

    Time frame: the day of treatment administration

    Assessed with the self-report Mystical experience Questionnaire (MEQ-30) with total man score ranging from 0 to 5, with higher scores indicating higher intensity of mystical experience

  2. heart rate

    Time frame: day of treatment administration

    beats per minute

  3. Self-rated anxiety

    Time frame: day of treatment administration

    Self-rated anxiety using a 0-100 visual analogue scale (VAS), with higher scores indicating higher anxiety

  4. Young Schema Questionnaire - Rasch version

    Time frame: Baseline (screening or preparation visit, before first psychedelic session), immediately after each psychedelic session (sessions 1-3, up to 9 months) and 1 month after each psychedelic session (sessions 1-3, up to 12 months after baseline)

    116-item self-report questionnaire assessing 20 early maladaptive schemas. Items are rated on a 6-point Likert scale (1 = completely untrue of me, 6 = describes me perfectly). Higher scores indicate greater schema intensity; schema-specific and overall mean scores can be derived.

Sponsors and collaborators

Lead sponsor

University Hospital, Geneva

Other

Registry information

Important dates

Study start
2020
Primary completion
2025
Study completion
2025
First posted
Sep 10, 2025
Registry last updated
Oct 2, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.