A 12-Week CBT + Motivation Program for Cannabis Use Disorder: Patients Used Less and Felt Better | Research

The takeaway

After 12 weeks of group therapy combining cognitive behavioral therapy and motivational enhancement, cannabis use disorder patients used less cannabis, had fewer cravings, and improved on depression, anxiety, and self-efficacy.

Read this if you're struggling with cannabis use and wondering whether therapy can help — this structured group program showed broad improvements across use, cravings, and mental health.

What the researchers found

Cannabis use disorder (CUD) is increasingly recognized as a real clinical condition, but treatment options have been slow to develop. This study evaluated a structured 12-week outpatient group therapy program at Toronto's Centre for Addiction and Mental Health — one of Canada's premier addiction treatment centers.

The program combined two evidence-based approaches: cognitive behavioral therapy (CBT), which helps patients identify and change thought patterns and behaviors that drive cannabis use, and motivational enhancement therapy (MET), which builds internal motivation to change. The group format added peer support and shared accountability.

The results were encouraging across the board. After treatment, participants showed lower cannabis use, more days of abstinence, fewer cannabis-related problems, reduced cravings, less severe withdrawal symptoms, and improved self-efficacy (confidence in their ability to stay abstinent). Depression and anxiety scores also improved.

Treatment retention — always a challenge in addiction treatment — was assessed by tracking clinic attendance. Client satisfaction, measured by anonymous feedback, was positive. The researchers also explored what predicted better outcomes and retention, looking for patterns that could help match patients to treatment.

This is important practical evidence because most cannabis treatment research has tested individual therapy. Group therapy is more cost-effective and more widely scalable, making it relevant for the many treatment programs facing long waitlists for cannabis-related concerns.

Why it matters

As cannabis use increases and more people develop problematic use patterns, accessible treatment options are urgently needed. Individual therapy is effective but expensive and limited in availability. This group-based CBT+MET program showed meaningful improvements in a real-world clinical setting, offering a scalable model that other treatment centers could adopt. The combination of reduced use AND improved mental health symptoms is particularly valuable since depression and anxiety commonly co-occur with CUD.

The numbers in context

12-week program. Treatment setting: outpatient group therapy at Centre for Addiction and Mental Health, Toronto. Post-treatment improvements: lower cannabis use, more abstinence days, reduced craving, fewer withdrawal symptoms, improved self-efficacy, lower depression and anxiety scores. Client satisfaction was positive. Specific effect sizes and retention rates were measured but detailed in the full paper.

How the study worked

Retrospective observational cohort study using medical records and self-report assessments from treatment-seeking cannabis users at the Centre for Addiction and Mental Health, Toronto. Pre- and post-treatment measures: cannabis use, cannabis-related problems, craving, withdrawal symptoms, self-efficacy, depression, and anxiety. Treatment retention calculated from attendance records. Client satisfaction assessed via anonymous feedback survey. Exploratory analyses examined predictors of outcomes and retention.

Who was studied

Participants were treatment-seeking cannabis users at the Centre for Addiction and Mental Health, Toronto.

What this study cannot tell us

Retrospective design without a control group — improvements could partly reflect natural recovery, regression to the mean, or motivation to change that existed before treatment began. Self-report measures are subject to social desirability bias, especially in a treatment setting. No long-term follow-up to assess whether improvements persisted after the 12-week program ended. Single-center study at a well-resourced addiction hospital — results may differ in less specialized settings.

How to read the evidence

Retrospective observational study without a control group. The consistent improvements across multiple measures are encouraging, but the lack of comparison group and randomization means the evidence is preliminary.

When this study was published

Published in 2023. Treatment research for cannabis use disorder continues to expand as CUD gains clinical recognition.

The bigger picture

This connects to the withdrawal and quitting studies throughout the database. RTHC-00037 (Budney's withdrawal timeline) established that cannabis withdrawal is real and clinically significant. RTHC-00053 (voucher-based therapy) tested a different behavioral approach. This study adds a group CBT+MET model to the treatment toolkit. Together, they show that behavioral treatments for CUD work — the question is which approaches work best for which patients.

Replication

Not stated in abstract.

Funding

Not reported in abstract.

Conflicts of interest

Not reported in abstract.

Questions still open

How do outcomes compare to individual therapy or other group formats? Do improvements persist at 6 and 12 months post-treatment? Would adding pharmacotherapy (like NAC or gabapentin) to the group program improve outcomes? Which patients benefit most from group versus individual treatment?

Read the original research

Implementation and Preliminary Evaluation of a 12-Week Cognitive Behavioural and Motivational Enhancement Group Therapy for Cannabis Use Disorder.

Substance abuse : research and treatment, 17, 11782218231205840

Substance Abuse: Research and Treatment is a peer-reviewed journal focusing on addiction research.

View on PubMed ↗Publisher’s paper ↗

Citation

Trick, Leanne; Butler, Kevin; Bourgault, Zoe; Vandervoort, Julianne; Le Foll, Bernard. (2023). Implementation and Preliminary Evaluation of a 12-Week Cognitive Behavioural and Motivational Enhancement Group Therapy for Cannabis Use Disorder.. Substance abuse : research and treatment, 17, 11782218231205840. https://doi.org/10.1177/11782218231205840