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Study on the Effects of Psilocybin (COMP360) for Adults with Treatment-Resistant Depression

Verified siteInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying treatment-resistant depression, a condition where individuals do not respond to typical depression treatments. The study will explore the effects of a medication called Psilocybin, which is being tested under the code name COMP360. Participants will receive two initial doses of this medication, either 25 mg or 1 mg, in capsule form. The medication will be taken orally, meaning it is swallowed. The purpose of the study is to see if Psilocybin can help improve symptoms of depression in people who have not found relief with other treatments.

During the study, participants will receive psychological support alongside the medication. The study will last for a period of 46 weeks, with the main focus on observing changes in depression symptoms by the sixth week. The study is designed to be double-blind, meaning neither the participants nor the researchers will know who is receiving which dose, to ensure unbiased results. A placebo will also be used in the study to compare the effects of the medication.

The trial aims to provide valuable information on the safety and effectiveness of Psilocybin for those with treatment-resistant depression. By comparing the effects of different doses, researchers hope to determine the best approach for using this medication to help improve the lives of those affected by this challenging condition.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial administration

    The trial involves two initial administrations of a medication called COMP360, which contains the active substance psilocybin. This medication is provided in the form of a capsule and is taken orally.

    The first administration will involve either a 25 mg dose or a 1 mg dose of COMP360. The specific dose is determined randomly and is part of the study's design to compare the effects of different dosages.

  2. Step 2

    Psychological support

    During the trial, psychological support is provided to assist in managing the symptoms of depression. This support is an integral part of the treatment process and accompanies the administration of the medication.

  3. Step 3

    Monitoring and assessment

    The primary goal of the trial is to assess the improvement in depression symptoms at Week 6. This is measured using a tool called the MADRS (Montgomery-Åsberg Depression Rating Scale), which evaluates the severity of depression.

    Participants will be monitored regularly to track changes in their depression symptoms and to ensure their safety throughout the trial.

  4. Step 4

    Second administration

    A second administration of COMP360 will occur, following the same dosage as the initial administration. This is to further evaluate the efficacy and safety of the treatment.

  5. Step 5

    Final evaluation

    At the end of the trial period, a final evaluation will be conducted to determine the overall effectiveness of the treatment in reducing symptoms of treatment-resistant depression.

    The results will be compared to the baseline measurements taken at the start of the trial to assess any changes in the MADRS score.

Who can join the trial?

6 criteria

  • Must be **18 years or older** at the time of screening.
  • Must have **major depression** without any psychotic features. This means depression without symptoms like hallucinations or delusions.
  • If this is the first time experiencing a major depressive episode, it must have lasted **at least 6 months but less than 2 years** at the time of screening.
  • Must have a **MADRS total score of 20 or higher** at both screening and baseline. MADRS is a scale used to measure the severity of depression symptoms.
  • Must have **treatment-resistant depression (TRD)**, which means not responding to at least two, but no more than four, different medications for the current episode of depression.
  • Must have successfully **stopped taking any medications that are not allowed** in the study at least two weeks before the baseline visit, if this applies.

Who cannot join the trial?

10 criteria

  • Individuals who have a history of severe allergic reactions to the study medication.
  • Participants with a current diagnosis of another major psychiatric disorder, such as schizophrenia or bipolar disorder.
  • People who have a significant medical condition that could interfere with the study, like uncontrolled high blood pressure or heart disease.
  • Individuals who are currently pregnant or breastfeeding.
  • Participants who have used certain medications or treatments that could affect the study results within a specific time frame before the study starts.
  • People who have a history of substance abuse or dependence within the past year.
  • Individuals who are unable to comply with the study procedures or follow-up visits.
  • Participants who have participated in another clinical trial within a certain period before this study.
  • People who have a history of suicidal behavior or thoughts that could pose a risk during the study.
  • Individuals who are considered vulnerable, such as those unable to give informed consent.
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Investigated drugs

COMP360 is a medication being studied for its potential to help people with treatment-resistant depression. In this trial, it is given to participants to see if it can improve symptoms of depression. The study involves two administrations of COMP360, and it is provided along with psychological support to see how effective and safe it is for those who have not responded to other treatments for depression.

What is already known about the treatment

COMP360 – This medication is administered orally in the form of capsules and is currently being studied in clinical trials for its potential use in treating treatment-resistant depression. It is in the experimental phase and not yet widely recognized in medical literature as a standard treatment. The main therapeutic indication is to alleviate symptoms of depression in individuals who have not responded to other treatments. At the molecular level, COMP360 is believed to work by modulating serotonin receptors in the brain, which can influence mood and emotional states. It is classified pharmacologically as a psychedelic compound.

Investigated diseases

Treatment-resistant depression – Treatment-resistant depression is a form of major depressive disorder that does not respond to standard treatments, such as antidepressant medications and psychotherapy. Individuals with this condition continue to experience persistent depressive symptoms despite trying multiple treatment options. The progression of this disease can vary, with some individuals experiencing chronic symptoms, while others may have periods of improvement followed by relapses. The lack of response to treatment can significantly impact daily functioning and quality of life. Understanding and managing this condition often requires exploring alternative therapeutic approaches.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-505268-12-00Protocol codeCOMP 006Estimated enrolment556 patientsSponsorCompass Pathfinder Limited

sourced from the EU Clinical Trials Register and site verification

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