Massive Review: How Cannabis Affects the Developing Adolescent Brain
A systematic review of 90 neuroimaging studies found preliminary evidence that adolescent cannabis use is associated with structural and functional alterations in multiple brain networks.
Quick Facts
What This Study Found
Across 90 studies including 9,441 participants (3,924 cannabis users, 5,517 non-users), preliminary evidence pointed to alterations in frontoparietal, frontolimbic, frontostriatal, and cerebellar regions among adolescent and emerging adult cannabis users.
Key Numbers
90 studies; 9,441 total participants; 3,924 cannabis users; 5,517 non-users; alterations in 4 major brain networks
How They Did This
Systematic search of Medline and PsycInfo with additional non-systematic sources, identifying 90 structural and functional neuroimaging studies of cannabis use during adolescence and emerging adulthood.
Why This Research Matters
With cannabis legalization expanding and adolescent perceptions of harm declining, establishing what happens to the developing brain during cannabis exposure is critical for public health messaging and clinical guidance.
The Bigger Picture
This is the most comprehensive neuroimaging review of adolescent cannabis effects to date. While findings point toward brain changes, the authors emphasize that larger, more rigorous studies are needed to separate risk factors from consequences.
What This Study Doesn't Tell Us
Divergent results across studies make definitive conclusions difficult. Most studies are cross-sectional, so risk factors for cannabis use and consequences of use are difficult to disentangle.
Questions This Raises
- ?Are the observed brain changes reversible with abstinence?
- ?Do cannabis potency and frequency of use moderate brain effects?
- ?Are there critical windows during adolescence when the brain is most vulnerable?
Trust & Context
- Key Stat:
- 90 studies, 9,441 participants reviewed
- Evidence Grade:
- Comprehensive systematic review of 90 studies, though individual study quality varies and most are cross-sectional.
- Study Age:
- Published in 2022
- Original Title:
- Systematic review of structural and functional neuroimaging studies of cannabis use in adolescence and emerging adulthood: evidence from 90 studies and 9441 participants.
- Published In:
- Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 47(5), 1000-1028 (2022)
- Authors:
- Lichenstein, Sarah D(3), Manco, Nick, Cope, Lora M(2), Egbo, Leslie, Garrison, Kathleen A, Hardee, Jillian, Hillmer, Ansel T, Reeder, Kristen, Stern, Elisa F, Worhunsky, Patrick, Yip, Sarah W
- Database ID:
- RTHC-04006
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
What brain regions are affected by adolescent cannabis use?
The review found preliminary evidence of alterations in frontoparietal (attention/executive function), frontolimbic (emotion regulation), frontostriatal (reward processing), and cerebellar (coordination/cognition) regions.
Does cannabis permanently change the adolescent brain?
The review could not determine whether changes are permanent because most studies are cross-sectional. The authors specifically called for research on whether cannabis effects are reversible with abstinence.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-04006APA
Lichenstein, Sarah D; Manco, Nick; Cope, Lora M; Egbo, Leslie; Garrison, Kathleen A; Hardee, Jillian; Hillmer, Ansel T; Reeder, Kristen; Stern, Elisa F; Worhunsky, Patrick; Yip, Sarah W. (2022). Systematic review of structural and functional neuroimaging studies of cannabis use in adolescence and emerging adulthood: evidence from 90 studies and 9441 participants.. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 47(5), 1000-1028. https://doi.org/10.1038/s41386-021-01226-9
MLA
Lichenstein, Sarah D, et al. "Systematic review of structural and functional neuroimaging studies of cannabis use in adolescence and emerging adulthood: evidence from 90 studies and 9441 participants.." Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 2022. https://doi.org/10.1038/s41386-021-01226-9
RethinkTHC
RethinkTHC Research Database. "Systematic review of structural and functional neuroimaging ..." RTHC-04006. Retrieved from https://rethinkthc.com/research/lichenstein-2022-systematic-review-of-structural
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.