High-Intensity Exercise Did Not Repair Brain Changes From Cannabis Use Disorder
A 12-week high-intensity interval training program did not improve hippocampal brain structure, cognition, or mental health in people with cannabis use disorder who continued using, though participants showed they could stick with regular exercise programs.
Quick Facts
What This Study Found
Hippocampal integrity (a composite of brain volume, structural connectivity, and neurochemistry) did not improve after 12 weeks of HIIT compared to strength training in adults with moderate to severe CUD. Neither cognitive nor mental health secondary outcomes improved. However, participants showed strong exercise adherence (80% completion rate, averaging 29 of 36 sessions).
Key Numbers
59 participants randomized; mean age 27; 80% male; 80% completed the 12-week program; averaged 29 of 36 sessions; brain MRI measured hippocampal volume, fractional anisotropy, and N-acetylaspartate
How They Did This
Randomized, single-blind, comparator-controlled clinical trial (BEAT trial) at Monash University BrainPark. 59 adults with moderate-severe CUD randomized 1:1 to HIIT (high lactate) or strength/resistance training (low lactate, active control), 3x/week for 12 weeks. Brain MRI at baseline and post-intervention. Participants were not required to stop cannabis use.
Why This Research Matters
Exercise has been proposed as a potential treatment for addiction, but this rigorous trial found it did not reverse CUD-related brain changes while people kept using. The strong adherence rate is the silver lining -- it shows people with CUD can commit to structured exercise programs, which could potentially reduce cravings.
The Bigger Picture
This is one of the first rigorous RCTs testing whether exercise can reverse cannabis-related brain changes. The null result is important -- it suggests that continued cannabis use may counteract any neuroprotective benefits of exercise, or that 12 weeks may not be long enough.
What This Study Doesn't Tell Us
Small sample (59 participants). Predominantly male (80%). Participants continued cannabis use during the trial. 12-week duration may be insufficient. Active control (strength training) may also have neurological benefits, potentially masking between-group differences.
Questions This Raises
- ?Would exercise improve brain outcomes in people who reduce or stop cannabis use simultaneously?
- ?Would a longer intervention period show different results?
- ?Does the craving reduction from exercise translate to reduced cannabis consumption over time?
Trust & Context
- Key Stat:
- 80% of CUD participants completed the 12-week exercise program
- Evidence Grade:
- Well-designed RCT published in JAMA Psychiatry with MRI outcomes, but small sample size and the decision to allow continued cannabis use limits conclusions about exercise potential.
- Study Age:
- Published in 2025 with trial conducted 2018-2022.
- Original Title:
- High-Intensity Exercise and Hippocampal Integrity in Adults With Cannabis Use Disorder: A Randomized Clinical Trial.
- Published In:
- JAMA psychiatry, 82(12), 1240-1245 (2025)
- Authors:
- Richardson, Karyn E, Suo, Chao(6), Albertella, Lucy(3), Maleki, Suzan, Coxon, James, Hendrikse, Josh, Hughes, Sam, Pitt, Joseph, Kayayan, Edouard, Brown, Catherine, Nguyen, Liam, Solowij, Nadia, Lubman, Dan I, Segrave, Rebecca, Yücel, Murat
- Database ID:
- RTHC-07489
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
Does this mean exercise is useless for cannabis addiction?
Not necessarily. The study found exercise did not repair brain changes while people continued using cannabis, but it did show CUD patients can stick with exercise programs and that exercise may reduce cravings. Exercise combined with reduced use might produce different results.
What is hippocampal integrity?
The hippocampus is a brain region important for memory and learning. "Integrity" here refers to a composite measure of its volume, structural connectivity, and neurochemistry. Cannabis use disorder is associated with changes in hippocampal structure.
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Cite This Study
https://rethinkthc.com/research/RTHC-07489APA
Richardson, Karyn E; Suo, Chao; Albertella, Lucy; Maleki, Suzan; Coxon, James; Hendrikse, Josh; Hughes, Sam; Pitt, Joseph; Kayayan, Edouard; Brown, Catherine; Nguyen, Liam; Solowij, Nadia; Lubman, Dan I; Segrave, Rebecca; Yücel, Murat. (2025). High-Intensity Exercise and Hippocampal Integrity in Adults With Cannabis Use Disorder: A Randomized Clinical Trial.. JAMA psychiatry, 82(12), 1240-1245. https://doi.org/10.1001/jamapsychiatry.2025.2319
MLA
Richardson, Karyn E, et al. "High-Intensity Exercise and Hippocampal Integrity in Adults With Cannabis Use Disorder: A Randomized Clinical Trial.." JAMA psychiatry, 2025. https://doi.org/10.1001/jamapsychiatry.2025.2319
RethinkTHC
RethinkTHC Research Database. "High-Intensity Exercise and Hippocampal Integrity in Adults ..." RTHC-07489. Retrieved from https://rethinkthc.com/research/richardson-2025-highintensity-exercise-and-hippocampal
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.