High-Intensity Exercise Did Not Repair Brain Changes From Cannabis Use Disorder

What the researchers 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).

Why it 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 numbers in context

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 the study worked

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.

What this study cannot 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.

How to read the evidence

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.

When this study was published

Published in 2025 with trial conducted 2018-2022.

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.

Questions still open

• 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?

Common questions

Read the original research

High-Intensity Exercise and Hippocampal Integrity in Adults With Cannabis Use Disorder: A Randomized Clinical Trial.

JAMA psychiatry, 82(12), 1240-1245

Citation

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

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