Cannabis Use Disorder, ModeratePhase 2PSI_CUDNCT06225232
Psilocybin in the Treatment of Cannabis Use Disorder: A-Proof-of-Concept Study
A Phase 2 study testing Psilocybin combined with Psychotherapy in people with Cannabis Use Disorder, Moderate and Cannabis Use Disorder, Severe, run by McMaster University at 1 site in Canada.
Trial summary
Cannabis is the most commonly used psychoactive substance in Canada (Lowry \& Corsi, 2020). A sub-group of cannabis users develop a condition known as Cannabis Use Disorder (CUD), which is defined as a regular pattern of cannabis use that causes performance difficulty at work, school and relationships (Hasin et al.… Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Cannabis Use Disorder, Moderate, Cannabis Use Disorder, Severe
- What is being tested?
- Psilocybin combined with Psychotherapy
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteCanada
- Study dates
- 21 Mar 2025to Dec 2026
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Signed Informed Consent Form.
- Able to show documentation of identity.
- Fluent in speaking and reading English and able to complete rating scales and assessments.
- Between the ages of 18 to 65.
- At Screening, meet criteria for CUD diagnosis of at least moderate severity as per the MINI Plus
- Expressed a wish to reduce or stop cannabis use.
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- Medically healthy based on physician review of CBC, electrolytes, liver function test, kidney function tests and ECG.
- Has a stable residence for the duration of the study.
- Agree to comply with the protocol requirements set out by the study.
- Consent to providing regular check-ins and follow-up regarding any medical conditions, procedures and adverse events.
- If of child-bearing potential, female participants must agree to use an adequate birth control method (IUD, injected or implanted hormonal methods, abstinence, vasectomy of the partner/partners, or double barrier contraception i.e. condoms plus diaphragm, or diaphragm plus spermicide) for the duration of the study. Male participants should agree to using condoms with spermicide throughout the trial in addition to the use of an adequate contraceptive by their partner of childbearing potential.
- Following discharge from the dosing sessions, agree to have another individual accompany them home from the study site and stay with them overnight.
Who cannot join
- Meet DSM-5 criteria for lifetime history of bipolar disorder, schizophrenia, or other psychotic disorders, personality disorders, delirium, dementia and amnesic and other cognitive disorders, or are in a current agitated state.
- Have first-degree biological relatives (parents or full siblings) with past or present history of schizophrenia, bipolar disorder and any other psychosis.
- Meet DSM-5 criteria for panic disorder or seizure disorders.
- Meet DSM-5 criteria for dependence of any substance other than cannabis or tobacco in the past 6 months.
- Positive urine drug screen for substances tested with the exception of cannabis
- History of serotonergic psychedelic use in the past year and over 5 times of lifetime use (psilocybin, LSD, Ayahuasca, mescaline, DMT).
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- Current treatment with psychotropic agents including stimulants, anti-psychotic agents, benzodiazepines and tri-cyclic anti-depressants. Concurrent treatment with Selective Serotonin Reuptake Inhibitors and Serotonin Noradrenalin Reuptake Inhibitors will be allowed, provided the dose has been stable for 4 weeks and remains stable during the study.
- History of cardiovascular diseases or uncontrolled hypertension that is not successfully treated or any other medical condition that might pose a risk to the participant in the opinion of the study physician.
- Are receiving concurrent psychotherapy for CUD.
- Are reasonably judged to present a serious suicide risk as determined by Columbia Suicide Severity Rating Scale or expressed homicide risk, who have enacted suicidal behaviors within 6 months prior to intake, or w ho are likely to require psychiatric hospitalization during the study.
- Participants of childbearing potential with a positive pregnancy test at screening or prior to dosing sessions, or are pregnant, breast feeding, and who are not using an acceptable means of birth control for the duration of the study.
- Are unable to fully understand the potential risks and benefits of the study and give informed consent.
- Are currently or planning on participating in other interventional clinical trials during this study.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: An 8-week Phase 2 Clinical Trial to Evaluate the Safety, Tolerability and Efficacy of Psilocybin-assisted-psychotherapy in Adults With Cannabis Use Disorder: A Proof-of-Concept Study
Cannabis is the most commonly used psychoactive substance in Canada (Lowry \& Corsi, 2020). A sub-group of cannabis users develop a condition known as Cannabis Use Disorder (CUD), which is defined as a regular pattern of cannabis use that causes performance difficulty at work, school and relationships (Hasin et al., 2013). A review of current treatments available for CUD indicate the lack of a pharmacological and psychological treatment with high success rates, which highlights the importance of exploring potential psychosocial interventions for the treatment of CUD. Given the evidence of psilocybin's therapeutic potential in the treatment of substance use disorders (de Veen et al., 2017), we aim to conduct a study using psilocybin-assisted-psychotherapy in the treatment of CUD. The study aims to evaluate the feasibility, safety, tolerability and potential therapeutic effect of 2 doses [25 mg] of psilocybin administered as part of an 8-week Motivational Enhancement Therapy (MET) and supportive therapy. This trial will be the first to evaluate the potential treatment effects of psilocybin on symptoms of CUD.
- Being tested
- Psilocybin combined with Psychotherapy
- Keywords
- Cannabis Use Disorder, Psilocybin, Motivational Enhancement Therapy
- Medical subject headings
- Lymphoma, Follicular
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Psilocybin combined with PsychotherapyDrug
The intervention consists of a 9-week treatment protocol that is based on supportive psychotherapy and Motivational Enhancement Therapy. Overall, the therapy course includes 8 motivational enhancement therapy sessions and two experimental drug sessions.
| Study group | Role | What they receive |
|---|---|---|
| Single Arm | Experimental | This is an open-label single arm intervention trial. Participants in this arm will be offered both drug and psychotherapy as part of their 9-week intervention. Receives: Drug: Psilocybin combined with Psychotherapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of spontaneously reported adverse events and serious adverse events from baseline to the nine-week endpoint
frequency, type and severity of outcomes are recorded
Measured: 9 weeks
Percent of recruited participants who discontinue or are lost to follow up before completing the 9-ween treatment protocol
frequency of cases of withdrawal and lost to follow up are documented and a percent is calculated based on the total number of participants recruited in this study.
Measured: 9 weeks
Secondary outcomes (4)
Feasibility measured by number of individuals who express interest by contacting the study team, percent of individuals who are screened as eligible to those who contact the study, percent of those who complete the trial to those who are enrolled
Reported in frequency and percentages
Measured: 9 weeks
Efficacy a: frequency and amount of cannabis use, as measured by the Timeline Follow Back from baseline to the nine-week end point
This is measured using the Timeline Follow Back tool
Measured: 9 weeks
Efficacy b: Severity of symptoms associated with Cannabis Use Disorder as measured by Self-Reported Symptoms of Cannabis Use Disorder from baseline to 9 week endpoint
Self-Reported Symptoms of Cannabis Use Disorder
Measured: 9 weeks
Efficacy c: Changes in Urinary Cannabinoids from baseline to the nine-week endpoint
Urinary Cannabinoid Test
Measured: 9 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jan 2024
- Study start21 Mar 2025
- Primary completionDec 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cannabis Use Disorder, ModerateStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 16 participants (estimated)
Sponsor and investigators
- Lead sponsor
- McMaster University
- Sponsor type
- University, hospital or other
- Collaborators
- Michael G. DeGroote Centre for Medicinal Cannabis Research
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06225232
- Sponsor's protocol ID
- PSI_CUD
- Acronym
- PSI_CUD
- Status last verified
- Aug 2026
- First submitted
- 4 Jan 2024
- Last updated
- 31 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 31 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An 8-week Phase 2 Clinical Trial to Evaluate the Safety, Tolerability and Efficacy of Psilocybin-assisted-psychotherapy in Adults With Cannabis Use Disorder: A Proof-of-Concept Study
- ClinicalTrials.gov ID
- NCT06225232
- Acronym / sponsor ID
- PSI_CUD / PSI_CUD
- Keywords
- Cannabis Use Disorder, Psilocybin, Motivational Enhancement Therapy
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 16 participants (estimated)
- Lead sponsor
- McMaster UniversityUniversity, hospital or other
- Collaborators
- Michael G. DeGroote Centre for Medicinal Cannabis Research
- Study start
- 21 Mar 2025 (actual)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 25 Jan 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Cannabis is the most commonly used psychoactive substance in Canada (Lowry \& Corsi, 2020). A sub-group of cannabis users develop a condition known as Cannabis Use Disorder (CUD), which is defined as a regular pattern of cannabis use that causes performance difficulty at work, school and relationships (Hasin et al., 2013). A review of current treatments available for CUD indicate the lack of a pharmacological and psychological treatment with high success rates, which highlights the importance of exploring potential psychosocial interventions for the treatment of CUD. Given the evidence of psilocybin's therapeutic potential in the treatment of substance use disorders (de Veen et al., 2017), we aim to conduct a study using psilocybin-assisted-psychotherapy in the treatment of CUD. The study aims to evaluate the feasibility, safety, tolerability and potential therapeutic effect of 2 doses [25 mg] of psilocybin administered as part of an 8-week Motivational Enhancement Therapy (MET) and supportive therapy. This trial will be the first to evaluate the potential treatment effects of psilocybin on symptoms of CUD.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Single Arm | Experimental | Drug: Psilocybin combined with PsychotherapyThis is an open-label single arm intervention trial. Participants in this arm will be offered both drug and psychotherapy as part of their 9-week intervention. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (12 listed)
- Signed Informed Consent Form.
- Able to show documentation of identity.
- Fluent in speaking and reading English and able to complete rating scales and assessments.
- Between the ages of 18 to 65.
- At Screening, meet criteria for CUD diagnosis of at least moderate severity as per the MINI Plus
Key exclusion criteria (13 listed)
- Meet DSM-5 criteria for lifetime history of bipolar disorder, schizophrenia, or other psychotic disorders, personality disorders, delirium, dementia and amnesic and other cognitive disorders, or are in a current agitated state.
- Have first-degree biological relatives (parents or full siblings) with past or present history of schizophrenia, bipolar disorder and any other psychosis.
- Meet DSM-5 criteria for panic disorder or seizure disorders.
- Meet DSM-5 criteria for dependence of any substance other than cannabis or tobacco in the past 6 months.
- Positive urine drug screen for substances tested with the exception of cannabis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Psilocybin combined with PsychotherapyThe intervention consists of a 9-week treatment protocol that is based on supportive psychotherapy and Motivational Enhancement Therapy. Overall, the therapy course includes 8 motivational enhancement therapy sessions and two experimental drug sessions. | Drug | Single Arm |
Primary outcome
Incidence of spontaneously reported adverse events and serious adverse events from baseline to the nine-week endpoint
Time frame: 9 weeks
frequency, type and severity of outcomes are recorded
Percent of recruited participants who discontinue or are lost to follow up before completing the 9-ween treatment protocol
Time frame: 9 weeks
frequency of cases of withdrawal and lost to follow up are documented and a percent is calculated based on the total number of participants recruited in this study.
4 secondary outcomes
Feasibility measured by number of individuals who express interest by contacting the study team, percent of individuals who are screened as eligible to those who contact the study, percent of those who complete the trial to those who are enrolled
Time frame: 9 weeks
Efficacy a: frequency and amount of cannabis use, as measured by the Timeline Follow Back from baseline to the nine-week end point
Time frame: 9 weeks
Efficacy b: Severity of symptoms associated with Cannabis Use Disorder as measured by Self-Reported Symptoms of Cannabis Use Disorder from baseline to 9 week endpoint
Time frame: 9 weeks
Efficacy c: Changes in Urinary Cannabinoids from baseline to the nine-week endpoint
Time frame: 9 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Aug 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Psilocybin combined with Psychotherapy in people with Cannabis Use Disorder, Moderate and Cannabis Use Disorder, Severe, run by McMaster University at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 12 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 31 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of spontaneously reported adverse events and serious adverse events from baseline to the nine-week endpoint (time frame: 9 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Aug 2026; AzTrials last refreshed its copy on 26 Oct 2026.