Systematic review of structural and functional neuroimaging studies of cannabis use in adolescence and emerging adulthood: evidence from 90 studies and 9441 participants.
Sarah D Lichenstein, Nick Manco, Lora M Cope, Leslie Egbo, Kathleen A Garrison, Jillian Hardee, Ansel T Hillmer, Kristen Reeder, Elisa F Stern, Patrick D. Worhunsky, Sarah W Yip
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology April 2022 DOI: 10.1038/s41386-021-01226-9 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Peer reviewed |
|---|---|
| Sample size | 9,441 |
| Population | Adolescents and emerging adults, including 3,924 cannabis users and 5,517 non-users |
| Topics | Cannabis |
| Key findings | The review reports preliminary evidence that adolescent cannabis use is associated with functional and structural alterations in frontoparietal, frontolimbic, frontostriatal, and cerebellar regions. The authors conclude that larger, more rigorous studies are needed to reconcile divergent results, separate risk factors from consequences of exposure, and clarify whether effects are reversible with abstinence. |
Abstract
Cannabis use peaks in adolescence, and adolescents may be more vulnerable to the neural effects of cannabis and cannabis-related harms due to ongoing brain development during this period. In light of ongoing cannabis policy changes, increased availability, reduced perceptions of harm, heightened interest in medicinal applications of cannabis, and drastic increases in cannabis potency, it is essential to establish an understanding of cannabis effects on the developing adolescent brain. This systematic review aims to: (1) synthesize extant literature on functional and structural neural alterations associated with cannabis use during adolescence and emerging adulthood; (2) identify gaps in the literature that critically impede our ability to accurately assess the effect of cannabis on adolescent brain function and development; and (3) provide recommendations for future research to bridge these gaps and elucidate the mechanisms underlying cannabis-related harms in adolescence and emerging adulthood, with the long-term goal of facilitating the development of improved prevention, early intervention, and treatment approaches targeting adolescent cannabis users (CU). Based on a systematic search of Medline and PsycInfo and other non-systematic sources, we identified 90 studies including 9441 adolescents and emerging adults (n = 3924 CU, n = 5517 non-CU), which provide preliminary evidence for functional and structural alterations in frontoparietal, frontolimbic, frontostriatal, and cerebellar regions among adolescent cannabis users. Larger, more rigorous studies are essential to reconcile divergent results, assess potential moderators of cannabis effects on the developing brain, disentangle risk factors for use from consequences of exposure, and elucidate the extent to which cannabis effects are reversible with abstinence. Guidelines for conducting this work are provided.
Comparable studies
Other systematic reviews and meta-analyses on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review | 2020 | Systematic review | |
| Neuroimaging in cannabis use: a systematic review of the literature Cannabis users and controls in neuroimaging studies | 2009 | Systematic review | |
| Human Laboratory Studies on Cannabinoids and Psychosis. Healthy human subjects and individuals with schizophrenia | 2016 | Systematic review | |
| Cannabis, a cause for anxiety? A critical appraisal of the anxiogenic and anxiolytic properties | 2020 | Systematic review | |
| Age-related differences in the impact of cannabis use on the brain and cognition: a systematic review | 2019 | Systematic review |