Cannabis use in adolescence linked to poor academic achievement and higher dropout rates

A systematic review and meta-analysis led by researchers at McMaster University has revealed that cannabis use during adolescence and young adulthood is associated with a decrease in academic achievement, increased school dropout rates, and lower university enrolment.

Published in JAMA Pediatrics, the study highlights the impacts of cannabis use on educational outcomes in young people.

The analysis focused on 63 studies involving more than 438,000 adolescents and young adults. Evidence suggests that cannabis use during the critical adolescent years of brain development can have lasting effects on academic success and future opportunities.

For Li Wang, the study’s lead author and associate professor at McMaster’s Department of Anesthesia, the findings are clear, “there is a strong association between cannabis use and negative academic outcomes, particularly for students who start using it before the age of 16 or use it frequently.”

One of the study’s most notable findings is the link between cannabis use and lower school grades. Adolescents who used cannabis had a 39 per cent decrease in the odds of achieving grades of B or higher.

Cannabis use also showed higher rates of absenteeism, with the odds of skipping school more than doubling compared to non-users.

The study also revealed that youth’s cannabis use doubled the odds of dropping out of school entirely.

“The transition from adolescence to adulthood is a crucial period, particularly for brain development and the formation of life skills,” says James MacKillop, director of the Michael G. DeGroote Centre for Medicinal Cannabis Research, and professor in McMaster’s Department of Psychiatry & Behavioural Neuroscience. “Cannabis use during these years not only affects cognitive function but also impacts key academic milestones that influence a person’s long-term success.”

In addition to lower high school grades and higher dropout rates, the study found that cannabis use reduced the chances of enrolling in university. The odds of adolescents who used cannabis pursuing higher education were 28 per cent less, and the odds of completing a postsecondary degree were 31 per cent less.

While the evidence linking cannabis use to unemployment was uncertain, the study did find a potential association. Cannabis users were shown to have a 50 per cent increase in the odds of being unemployed, further underscoring the long-term risks.

As a result, the researchers are calling for targeted public health interventions to prevent early cannabis use and potential academic consequences. “With the increasing legalization and social acceptance of cannabis, we must prioritize informed approaches, particularly for adolescents,” says Jason Busse, associate director of the Michael G. DeGroote Centre for Medicinal Cannabis Research, and professor in McMaster’s Department of Anesthesia. “Educating young people about cannabis risks and providing support to those who need it may help protect the future potential of younger generations.”