Testing Psilocybin with Therapy for Treatment of Gambling Disorder in Adults with Problem Gambling

What is this study about?

This study looks at gambling disorder, which is a condition where a person has difficulty controlling the urge to gamble despite negative consequences in their life. The study will test a treatment that combines special therapy sessions with psilocybin, a substance found in certain mushrooms that can affect thoughts and feelings. Some participants will receive PEX010 Psilocybin Capsules in different strengths (1.0 mg, 5.0 mg, or 25.0 mg), while others will receive placebo capsules. The capsules are taken by mouth. The purpose of the study is to see if it is possible to conduct a larger research study on this type of therapy for gambling disorder by checking if participants can stay in the study until the end of all planned activities.

The study will involve several visits where participants will receive either psilocybin or placebo during therapy sessions. During these sessions, participants will be closely watched for any changes in heart rate, blood pressure, and behavior or mood. Participants will also complete questionnaires at different times to measure things like their confidence in themselves, how they judge their own condition, their ability to be kind to themselves, their spiritual well-being, and their urges to gamble. Some participants will keep a daily journal to record their cravings. The study will also look at whether the strength of the experience during the psilocybin sessions relates to other personal factors measured at the start of the study.

Throughout the study, researchers will track any unwanted effects that participants experience and will check whether the treatment appears safe. They will also measure whether participants feel the treatment is helpful and whether they are satisfied with the number and length of therapy sessions. The study will assess if enough people agree to join and complete all the planned visits and procedures. Researchers will also gather feedback from both participants and healthcare providers about their experience with this treatment approach. Blood tests and heart tracings will be done to monitor safety.

1 Initial assessment and confirmation

Your diagnosis of gambling disorder will be confirmed according to established diagnostic criteria.

A blood test will be performed to assess your general health status.

An electrocardiogram will be conducted to check your heart function.

A urine test will be performed to screen for the presence of drugs.

If you are a woman of childbearing age, a pregnancy test will be performed and you will need to use highly effective contraception throughout the trial.

If you are a man of childbearing age, you will need to use effective contraception throughout the trial.

If you are taking any psychiatric medications, your dosage must have been stable or the treatment must have been started more than one month before entering the trial.

Baseline assessments will be completed, including questionnaires measuring personal self-efficacy, clinical severity, self-compassion, spirituality, and treatment expectations.

2 Randomization

You will be randomly assigned to one of two groups: the experimental group receiving psilocybin-assisted psychotherapy or the control group.

The assignment will be done by chance, similar to flipping a coin.

3 Treatment sessions

You will participate in scheduled treatment sessions that combine medication administration with psychotherapy support.

If assigned to the experimental group, you will receive PEX010 Psilocybin Capsules taken orally. The capsules contain a dry extract from psilocybe cubensis and may be provided in different strengths: 1.0 mg, 5.0 mg, or 25.0 mg of psilocybin.

If assigned to the control group, you will receive placebo capsules taken orally, which contain hypromellose but no active psilocybin.

You will receive two administration sessions during the treatment period.

During each administration session, your heart rate and blood pressure will be monitored regularly.

Your behavior and mood will be observed during the sessions using a standardized assessment grid.

After each administration session, you will complete a questionnaire measuring the intensity of your experience.

You will be asked to keep a daily journal recording the intensity, frequency, and duration of any gambling cravings you experience.

4 Follow-up assessments

After completing the treatment sessions, you will attend scheduled follow-up visits.

During these visits, you will complete the same questionnaires as at baseline to measure changes in personal self-efficacy, clinical severity, self-compassion, and spirituality.

Any side effects or health concerns will be documented throughout your participation.

Your risk of suicide will be assessed during the follow-up period.

5 End of study participation

Your participation will conclude after completing all scheduled visits and assessments.

A final evaluation will be conducted to assess your overall clinical improvement and the effectiveness of the treatment you received.

You will be asked to provide feedback about your experience with the treatment, including the duration, number, and frequency of sessions.

Who Can Join the Study?

You must be a man or woman aged 18 years or older
You must have a negative result on a urine drug test, which checks for the presence of drugs in your body
If you are a woman who can become pregnant, you must have a negative pregnancy test and use highly effective birth control methods to prevent pregnancy during the study
If you are a man who can father a child, you must use effective birth control methods during the study
If you are taking psychotropic medication, which are medicines that affect your mood, thoughts, or behavior (not including nicotine replacement products like patches or gum), your dose must have been stable or the treatment must have started more than one month ago
You must have a confirmed current diagnosis of gambling disorder, which is a condition where you have difficulty controlling gambling behavior, regardless of how mild or severe it is
You must be able to complete questionnaires about yourself on your own
You must be willing to start treatment for addiction, or your current treatment is not working well enough
You must agree to have a blood test and an electrocardiogram, which is a test that checks the electrical activity of your heart
You must be able to understand and speak French, both in writing and when spoken
You must sign a consent form before any study procedures begin, showing that you understand and agree to participate
You must be covered by French social security, which is the French healthcare system

Who Cannot Join the Study?

The study document does not list specific reasons why patients cannot participate in this trial
If you are interested in this study, a doctor or research team member will need to evaluate if you meet all requirements during a screening process
Generally, clinical trials may exclude patients based on other health conditions, medications they are taking, or other factors that could affect the study results or patient safety

Where you can join this trial?

Verified and Recommended Sites

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Verified Sites

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Other Sites

Site Name	City	Country	Status
Centre Hospitalier Universitaire De Nantes	Nantes	France

Trial status

Country	Status	Recruitment Start
France	Not yet recruiting	01.12.2025

Trial locations

Investigated drugs:

Psilocybin is a naturally occurring substance found in certain mushrooms that affects the brain and changes how a person thinks, feels, and perceives things. In this study, psilocybin is being tested as a treatment for gambling disorder when combined with psychotherapy sessions. The medication is used to help people who have difficulty controlling their gambling behavior by potentially changing their thought patterns and emotional responses.

Gambling Disorder – Gambling disorder is a behavioral condition characterized by persistent and repeated problematic gambling behavior that causes significant distress or impairment in personal, family, or work life. Individuals with this disorder experience a strong urge to gamble despite negative consequences, often needing to bet increasing amounts of money to achieve the desired excitement. The condition typically progresses from occasional gambling to more frequent and uncontrolled behavior patterns. People affected may become preoccupied with gambling, thinking about past gambling experiences or planning future bets. They often have difficulty controlling or stopping their gambling behavior, even when they recognize the problems it causes. The disorder can lead to financial difficulties, damaged relationships, and significant emotional distress over time.

Trial ID:

2025-522743-18-00

Protocol code:

RC25_0105

Trial Phase:

Therapeutic exploratory (Phase II)

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