Age-related differences in the impact of cannabis use on the brain and cognition: a systematic review
Claire M. Gorey, Lauren Kuhns, Eleni Smaragdi, Emese Kroon, Janna Cousijn
European Archives of Psychiatry and Clinical Neuroscience January 24, 2019 DOI: 10.1007/s00406-019-00981-7 via OpenAlex
Summary
Adolescence is a period of both risk and resilience regarding the harms of cannabis use. This systematic review examined whether age (adolescent vs. adult) moderates the relationship between cannabis exposure and cognition, drawing on both human and animal studies. The review does not offer a conclusive answer but generates four hypotheses: general executive functioning appears more impaired in adolescent frequent users than in adult frequent users; age effects may be strongest among very heavy and dependent users; craving and inhibitory control may not decrease as much post-intoxication in adolescents; and adolescents' vulnerability to reduced learning following cannabis use may not persist after sustained abstinence. If confirmed, these hypotheses could inform policy and prevention.
Study at a glance
| Characteristics | Systematic review Peer reviewed |
|---|---|
| Topics | Cannabis |
| Keywords | Effects of cannabis Cognition Abstinence Developmental psychology Psychological resilience |
| Citations | 118 |
| Key finding | The review does not offer a conclusive answer on the moderating role of age but generates hypotheses that general executive functioning is more impaired in adolescent frequent cannabis users, age effects may be strongest among very heavy users, craving and inhibitory control may persist more in adolescents post-intoxication, and learning deficits may not persist after sustained abstinence in adolescents. |
Abstract
The impact of cannabis on the adolescent compared to adult brain is of interest to researchers and society alike. From a theoretical perspective, adolescence represents a period of both risk and resilience to the harms of cannabis use and cannabis use disorders. The aim of this systematic review is to provide a critical examination of the moderating role of age on the relationship between cannabis use and cognition. To this end, we reviewed human and animal studies that formally tested whether age, adolescent or adult, changes the relationship between cannabis exposure and cognitive outcomes. While the results of this review do not offer a conclusive answer on the role of age, the novel review question, along with the inclusion of both human and animal work, has allowed for the formation of new hypotheses to be addressed in future work. First, general executive functioning seems to be more impaired in adolescent frequent cannabis users compared to adult frequent cannabis users. Second, age-effects may be most prominent among very heavy and dependent users. Third, craving and inhibitory control may not decrease as much post-intoxication in adolescents compared to adults. Lastly, adolescents' vulnerability to reduced learning following cannabis use may not persist after sustained abstinence. If these hypotheses prove correct, it could lead to important developments in policy and prevention efforts.