Rationale: Cannabis use during adolescence and cannabis potency have increased over time. More studies are assessing the negative effects of cannabis use during periods of brain development, which can impact students’ academic performance. Chronic cannabis use can alter the brain, causing impaired information processing, decreased cognition and memory, and reduced attention (Jacobus & Tapert, 2014). Prior evidence suggests that heavy cannabis use is associated with worse educational outcomes (Pacheco-Colón et al., 2019). This study clarifies the relationship between cannabis use and academic performance in adolescents and young adults.

Method: Reviewers combined results from 63 studies, exploring associations between cannabis and academic outcomes. Researchers evaluated school grades, school dropouts, school absenteeism, being held back, high school completion, university enrollment, postsecondary degree attainment, and unemployment in nearly half a million students, some of whom used cannabis.

Results: Early onset and/or heavy cannabis use was shown to negatively impact academic performance. Higher frequency use of cannabis was associated with lower school grades, worse attendance, lower college attendance, and decreased employment.
Meaning: Cannabis use is associated with negative effects on schooling and employment.