Tirzepatide in the Treatment of Cannabis Use Disorder: A Proof-of-Concept Study

June 22, 2026 updated by: M. Van Ameringen, McMaster University

A 12-Week Phase 4 Clinical Trial to Evaluate the Safety, Tolerability and Efficacy of Tirzepatide-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 Cannabis Use Disorder (CUD). CUD is a pattern of cannabis use that results in impairment in functioning, symptoms of tolerance, withdrawal, and distress (Hasin et al., 2013). Several pharmacological and psychosocial interventions have been evaluated for their efficacy in treating CUD, however they lack high success rates. GLP-1RA's have shown promising results in reducing food and alcohol cravings and intake (Bruns et al., 2024). Tirzepatide acts as both a GLP-1RA and a glucose-dependent insulinotropic polypeptide receptor agonist (Min & Bain, 2021). Tirzepatide has been reported to reduce alcohol consumption (Quddos et al., 2023), and therefore may have promising effects as a treatment for CUD. We aim to conduct a study using Tirzepatide-assisted-psychotherapy in the treatment of CUD. This study aims to evaluate the feasibility and tolerability of weekly injections of Tirzepatide combined with Motivational Enhancement Therapy in adults with CUD. This trial will be the first to examine the potential therapeutic effects of Tirzepatide in CUD.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

15

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Canada
    • Ontario
      • Hamilton, Ontario, Canada, L8S 1B8
        • MacAnxiety Research Centre
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 18 and above
  • DSM-5 Cannabis Use Disorder diagnosis of at least moderate severity (4+ DSM-5 symptoms)
  • 4 or more days of cannabis use per week
  • Treatment seeking
  • A Body Mass Index (BMI) ≥ 22

Exclusion Criteria:

  • Meet DSM-5 criteria for Cluster A or B personality disorders and/or unstable current bipolar disorder, schizophrenia, or psychotic disorder
  • Comorbid severe DSM-5 Major Depressive Disorder
  • Present a serious suicide risk or who are likely to require psychiatric hospitalization during the course of the study, as determined by the study physician and Columbia Suicide Severity Rating Scale
  • Any other mental health condition deemed incompatible by the study team
  • Meet DSM-5 criteria for alcohol or substance use disorder for any substance other than cannabis or tobacco in the past 6 months
  • Positive urine drug screen for any substance except cannabis
  • Concurrent addiction-focused psychotherapy in the past 6 months
  • Unstable management of an existing mental health condition or anticipation of a change to the treatment over the next 3 months
  • A personal or family history of medullary thyroid cancer or Multiple Endocrine Neoplasia syndrome type 2
  • Current unstable medical condition
  • A lifetime diagnosis of Diabetes
  • Females who are pregnant/nursing, or individuals in reproductive age who do not consent to using birth control during the study
  • Concomitant treatment with: other GLP-1 agonists, Contrave, bupropion, naltrexone, acamprosate within the past year. No lifetime treatment with tirzepatide.
  • Significant literacy, visual, or hearing problems
  • Co-enrollment in a clinical drug trial

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Single Arm
This is an open-label single arm intervention. All participants will be offered both Tirzepatide and psychotherapy over the 12-week treatment period.
Drug: Tirzepatide
Treatment will occur over a 12-week period, with once-weekly injections of escalating doses every 3 weeks from 2.5mg to 10mg. Tirzepatide will be used in conjunction with Motivational Enhancement Therapy (MET).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tolerability of Tirzepatide-Assisted-Psychotherapy for Cannabis Use Disorder.
Time Frame: From baseline to 12-week endpoint.

Tolerability will be measured by the percent of participants who discontinue the trial.

Tolerability will also be measured by the percent of participants who reach the target dose.
From baseline to 12-week endpoint.
Feasibility of Tirzepatide-Assisted-Psychotherapy for Cannabis Use Disorder.
Time Frame: From baseline to 12-week endpoint.
Feasibility will be evaluated based on the number of people who contact the study team, percent of people that contact who are eligible and percent of eligible participants who enroll.
From baseline to 12-week endpoint.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Frequency and amount of cannabis use
Time Frame: From baseline to 12-week endpoint.
The Enhanced Cannabis Timeline Follow Back (EC-TLFB) obtains information about frequency of cannabis use, amount used, types of cannabis products, and methods of administration.
From baseline to 12-week endpoint.
Severity of Cannabis Use Disorder symptoms
Time Frame: From baseline to 12-week endpoint
The Self-Reported Symptoms of Cannabis Use Disorder (SRSCUD) is a 13-item self-report form that allows individuals to rate the severity of their Cannabis Use Disorder on a scale from 1 to 4.
From baseline to 12-week endpoint
Cannabis cravings
Time Frame: From baseline to 12-week endpoint
The Marijuana Craving Questionnaire - Short Form (MCQ-SF) is a self-report 12-item questionnaire used to assess individual's cannabis craving experiences. Individuals rate items on a Likert scale from 1 (strongly agree) to 7 (strongly agree).
From baseline to 12-week endpoint
Cannabis withdrawal symptoms
Time Frame: From baseline to 12-week endpoint
The Marijuana Withdrawal Checklist (MWC) is a self-report 15-item questionnaire used to assess symptoms of cannabis withdrawal. Participants rate items on a Likert scale from 0 (not at all) to 3 (severe) based on their most recent period of cannabis abstinence.
From baseline to 12-week endpoint

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from baseline on the severity of anxiety symptoms
Time Frame: From baseline to 12-week endpoint
The Generalized Anxiety Disorder-7 (GAD-7) is a self-report 7-item questionnaire that measures anxiety symptom severity. Items are rated on a Likert scale from 0 (not at all) to 3 (nearly every day).
From baseline to 12-week endpoint
Change from baseline on Attention Deficit Hyperactivity Disorder symptom severity
Time Frame: From baseline to 12-week endpoint
The Barkley's Adult ADHD Rating Scale - I (BAARS-IV) is a 21 item self-report questionnaire that assesses ADHD symptom severity.
From baseline to 12-week endpoint
Change from baseline in depression symptoms
Time Frame: From baseline to 12-week endpoint.
The Patient Health Questionnaire-9 (PHQ-9) is a self-report measure with 9-items used to assess the presence of depression symptoms in the past 2 weeks. Items are scored on a Likert scale from 0 (not at all) to 3 (nearly every day).
From baseline to 12-week endpoint.
Change from baseline in functional impairment
Time Frame: From baseline to 12-week endpoint.
The Sheehan Disability Scale (SDS) is a self-report scale of functional impairment. Responses are based on an eleven-point scale from 0 (not at all) to 10 (extremely).
From baseline to 12-week endpoint.
Change from baseline in OCD symptoms
Time Frame: From baseline to 12-week endpoint.
The Obsessive Compulsive Inventory - Revised (OCI-R) is an 18-item self-report questionnaire that assesses various obsessions.
From baseline to 12-week endpoint.
Change in baseline quality of life
Time Frame: From baseline to 12-point endpoint.
The World Health Organization Quality of Life assessment (WHOQOL-BREF) is a self-report measure that assesses quality of life across physical health, psychological, social relationships, and environment domains. The WHOQOL-BREF consists of 26 items that are rated on a 5-point Likert scale.
From baseline to 12-point endpoint.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

McMaster University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

August 1, 2026

Primary Completion (Estimated)

July 31, 2028

Study Completion (Estimated)

July 31, 2028

Study Registration Dates

First Submitted

June 15, 2026

First Submitted That Met QC Criteria

June 22, 2026

First Posted (Actual)

June 26, 2026

Study Record Updates

Last Update Posted (Actual)

June 26, 2026

Last Update Submitted That Met QC Criteria

June 22, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Tirzep_CUD

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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