Large meta-analysis maps how youth cannabis use changes brain activation patterns
A meta-analysis of 45 fMRI studies found that cannabis-using youth showed altered brain activation in prefrontal and cingulate regions during cognitive tasks, with differences varying by sex, severity, and psychiatric comorbidity.
Quick Facts
What This Study Found
Cannabis-using youth showed greater activation in the rostral medial prefrontal cortex during executive control tasks and decreased activation in the dorsal medial prefrontal cortex and dorsal anterior cingulate during social cognition and emotion processing, compared to non-using peers.
Key Numbers
45 fMRI studies. 1,216 cannabis-using youth vs. 1,486 non-using controls. Brain activation differences varied by sex, cannabis use disorder severity, psychiatric comorbidity, and length of abstinence.
How They Did This
Systematic review and seed-based d mapping (SDM) meta-analysis of 45 fMRI studies comparing BOLD response in 1,216 cannabis-using youth and 1,486 non-using typically developing participants.
Why This Research Matters
Understanding how cannabis changes brain function in young people is critical because the adolescent brain is still developing. This meta-analysis provides the most comprehensive picture to date of where those changes occur.
The Bigger Picture
The finding that brain differences vary with sex, severity, and comorbidity suggests that youth cannabis use does not have a single uniform effect on the brain. Individual factors shape the neurological impact.
What This Study Doesn't Tell Us
Cross-sectional nature of most included studies makes it impossible to determine whether brain differences preceded or resulted from cannabis use. Heterogeneity in study designs and cannabis exposure measures.
Questions This Raises
- ?Do the observed brain activation differences reverse with sustained abstinence?
- ?Are predispositional brain differences driving both cannabis use and the observed activation patterns?
Trust & Context
- Key Stat:
- 45 studies, 1,216 cannabis-using vs. 1,486 non-using youth
- Evidence Grade:
- Large meta-analysis using validated SDM methodology across 45 fMRI studies with over 2,700 participants.
- Study Age:
- Published in 2022.
- Original Title:
- A Meta-Analysis of fMRI Studies of Youth Cannabis Use: Alterations in Executive Control, Social Cognition/Emotion Processing, and Reward Processing in Cannabis Using Youth.
- Published In:
- Brain sciences, 12(10) (2022)
- Authors:
- Hammond, Christopher J(6), Allick, Aliyah(2), Park, Grace(2), Rizwan, Bushra, Kim, Kwon, Lebo, Rachael, Nanavati, Julie, Parvaz, Muhammad A, Ivanov, Iliyan
- Database ID:
- RTHC-03900
Evidence Hierarchy
Combines results from multiple studies to find an overall pattern.
What do these levels mean? →Frequently Asked Questions
Does cannabis change the brains of young people?
This meta-analysis of 45 studies found cannabis-using youth showed different activation patterns in prefrontal and cingulate brain regions during cognitive and emotional tasks compared to non-using peers.
Do boys and girls show the same brain changes from cannabis?
No. The meta-analysis found that sex was correlated with brain activation differences between cannabis users and non-users, suggesting the neurological impact of cannabis varies between males and females.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-03900APA
Hammond, Christopher J; Allick, Aliyah; Park, Grace; Rizwan, Bushra; Kim, Kwon; Lebo, Rachael; Nanavati, Julie; Parvaz, Muhammad A; Ivanov, Iliyan. (2022). A Meta-Analysis of fMRI Studies of Youth Cannabis Use: Alterations in Executive Control, Social Cognition/Emotion Processing, and Reward Processing in Cannabis Using Youth.. Brain sciences, 12(10). https://doi.org/10.3390/brainsci12101281
MLA
Hammond, Christopher J, et al. "A Meta-Analysis of fMRI Studies of Youth Cannabis Use: Alterations in Executive Control, Social Cognition/Emotion Processing, and Reward Processing in Cannabis Using Youth.." Brain sciences, 2022. https://doi.org/10.3390/brainsci12101281
RethinkTHC
RethinkTHC Research Database. "A Meta-Analysis of fMRI Studies of Youth Cannabis Use: Alter..." RTHC-03900. Retrieved from https://rethinkthc.com/research/hammond-2022-a-metaanalysis-of-fmri
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.