Clinical trial Recruiting at 1 site Phase 2 Interventional Ages 18 and up

Psilocybin and trazodone in treatment-resistant depression

Official title: Efficacy of Psilocybin and Trazodone Combination in Treatment-resistant Depression: a Randomized Controlled Proof-of-concept Study (PSILOTRAZ)

Run by Centre Hospitalier St Anne · NCT07210112 · Data updated 2026-11-12

This study tests whether adding trazodone to psilocybin helps people with treatment-resistant depression see benefit with different trazodone doses.

Quick facts

PhasePhase 2
Study typeInterventional
Ages18 Years and up
SexAll
Enrollment112 (estimated)
SponsorCentre Hospitalier St Anne
Academic / other
Locations1 site (Paris)
StatusRecruiting
StartedJune 30, 2026
Main results expectedDecember 31, 2029
Study endsJune 30, 2030
Registry record updatedSeptember 21, 2026
Trial IDNCT07210112 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults with major depressive episodes who have not responded to at least two prior antidepressant treatments and meet DSM-5 criteria for non-psychotic major depression, with MADRS ≥ 20.

Probably not a fit

Individuals with active psychosis risk, certain psychiatric comorbidities, recent substance use disorders, or significant suicide risk may not benefit or may be excluded for safety.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This phase II, randomized, double-blind, placebo-controlled study compares four treatment arms in adults with major depressive disorder who have not responded to at least two antidepressants. All participants receive a fixed dose of psilocybin (25 mg) along with one of three trazodone conditions (placebo, 5 mg, or 30 mg) or a psilocybin/placebo control, to explore how 5-HT2A receptor blockade influences treatment effects. The trial is monocentric and uses stratification by gender, enrolling up to 112 participants. Primary outcomes focus on depressive symptom change, with safety monitoring throughout the intervention. The goal is to understand whether psilocybin’s antidepressant effects can be achieved partly independent of 5-HT2A receptor activation and whether trazodone co-administration alters risk-benefit balance.

Why it matters

Potential benefit: If successful, the approach could offer a new, potentially more effective option for people with treatment-resistant depression.

How similar studies have gone: Prior work suggests psilocybin can rapidly reduce depressive symptoms, but the additive role of 5-HT2A modulation remains to be proven, making this approach exploratory.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patient with major depressive episode without psychotic features according to DSM-5 criteria;
* Treatment-resistant depressive episode, i.e. failure to respond to at least two lines of antidepressant medication at an adequate dose and for a sufficient period of time (6 weeks according to the MGH-ATRQ);
* MADRS ≥ 20;
* Written signed informed consent;
* Patient covered by the social security system.

Exclusion Criteria:

Psychiatric comorbidities known from medical history or identified during inclusion assessment:

* Bipolar disorder;
* Schizophrenia and psychosis;
* Personal or family history of psychotic disorder;
* History of personality disorder;
* Post-traumatic stress disorder, obsessive-compulsive disorder, eating disorders;
* Alcohol or substance use disorder in past 12 months or positive urine toxins at time of assessment;
* Significant suicide risk, as defined by: (a) suicidal ideation as indicated by items 4 or 5 on the C-SSRS within the past six months, at Screening, during the Screening Period, or at Baseline (b) demonstrating suicidal behaviors in the past six months, or; (c). clinical assessment of significant suicidal risk or risk of self-injury during participant interview;
* Patient with a psychiatric decompensation following a previous use of psychedelic substance like LSD;

Comorbidities or somatic specificities:

* Pregnancy and breastfeeding women;
* Cardiovascular history (myocardial infarction, stroke, heart rhythm disorder, uncontrolled hypertension, QT interval prolongation, tachycardia and poor cardiovascular health);
* Uncontrolled diabetes;
* Uncontrolled thyroid disorder;
* Epilepsy;
* Parkinson's disease treated by selegiline or levodopa;
* HIV treated by ritonavir and indinavir;
* Active infection treated by erythromycin;
* Fungal infection treated by ketoconazole and itraconazole;
* Contraindications to MRI;

Concomitant therapies:

* 5-HT antagonist treatment2A (including quetiapine, olanzapine, aripiprazole);
* Lithium treatment;
* Treatment with buprenorphine or opioids, clonidine, methyldopa, digoxin, Monoamine oxidase inhibitors (MAOI), aldehyde dehydrogenase (ALDH) inhibitors and alcohol dehydrogenase (ADH) inhibitors, St. John's Wort, or warfarin should be discontinued completely before study drug administration;
* Use of electroconvulsive therapy and/or transcranial magnetic stimulation, during the current depressive episode; or lifetime vagus nerve stimulation, deep brain stimulation, and/or ablative neurosurgery;
* Use of psychedelics (psilocybin, lysergic acid, ayahuasca, mescaline and derivatives) during current episode;

Legal status:

* Persons deprived of their liberty by judicial or administrative decision, persons under compulsory psychiatric care;
* Persons under legal protection or unable to give consent;

Other:

\- Any clinical manifestation which, in the opinion of the investigator, may interfere with the interpretation of study results or constitute a health risk to the participant if he or she participates in the study.

Where it's running

  • GHU Paris Psychiatrie and Neurosciences
    Paris, France
    Recruiting

Study contacts

  • Principal investigator: Lucie BERKOVITCH, MD — GHU Paris Psychiatrie and Neurosciences - Neuromodulation Institute
  • Study coordinator: Lucie BERKOVITCH, MD
  • Email: l.berkovitch@ghu-paris.fr
  • Phone: +33 145657481

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.