Key messages:
- Cannabis use during adolescence and young adulthood is associated with poorer academic performance.
- Screening youths at elevated risk of initiating cannabis use could facilitate prevention and early intervention strategies.
- Further research to establish effective prevention programs is warranted.
Introduction
Adolescence and young adulthood are crucial periods for brain development. The increasing acceptance and legalization of cannabis have raised concerns about its impact on academic performance. Cannabis use can cause short-term cognitive impairments, such as memory loss and reduced attention. Chronic use during adolescence has been linked to long-term changes in brain structure, resulting in difficulties with information processing and a decline in cognitive abilities, memory, and attention in adulthood.
A recent systematic review on adolescent cannabis use and academic achievement found heavy cannabis use was associated with poorer educational outcomes. However, this review had several limitations, including the absence of statistical pooling of the associations, a failure to evaluate the risk of bias in individual studies, and a limited search period from 2014 to 2019.
Objective
This systematic review and meta-analysis investigated the relationship between cannabis use during adolescence and young adulthood and academic achievement.
Methods
MEDLINE, EMBASE, PsycInfo, CINAHL, Scopus, and Web of Science were searched from inception to November 10, 2023. Observational studies examining the association of cannabis use with academic outcomes were selected. The literature search identified 17,622 unique citations.
Results
Sixty-three studies, including 438,329 adolescents and young adults, were eligible for analysis. Moderate-certainty evidence showed cannabis use during adolescence and young adulthood was probably associated with lower school grades, less likelihood of high school completion, university enrollment, and postsecondary degree attainment; and increased school dropout rate and school absenteeism. Absolute risk effects ranged from 7% to 14%. Low-certainty evidence suggested cannabis use may be associated with increased unemployment, with an absolute risk increase of 9%. Subgroup analyses with moderate credibility showed worse academic outcomes for frequent cannabis users and for students who began cannabis use earlier.
Conclusions
Cannabis use during adolescence and young adulthood was probably associated with increases in school absenteeism and dropout; reduced likelihood of obtaining high academic grades, graduating high school, enrolling in university, and postsecondary degree attainment. Low-certainty evidence suggests cannabis use during adolescence and young adulthood may be associated with higher unemployment. More frequent use and earlier onset were associated with worse academic outcomes. Further research is needed to identify interventions and policies to address factors associated with early cannabis exposure.
