Teens Who Drink and Smoke Pot Have Poorer Academic Performance: Study

Alcohol, Marijuana and TeensAccording to a new study published online in the journal Addiction, teens who drink alcohol and use marijuana throughout middle school and high school are more likely to have worse outcomes in high school for academics and health.

The study, conducted by researchers at the nonprofit global policy think tank RAND Corporation, took place over seven years.

Alcohol, Marijuana and Teens: Survey Summary

  • 6,509 young people from 16 middle schools in Southern California participated in the study. Subjects were 50% male and 80% non-white.
  • Subjects were surveyed about their alcohol and marijuana use from 2008-2015 (so from the starting age of about 11.5-years-old to approximately 17-years-old by the study’s end).
  • Subjects completed five surveys in middle school and two surveys (online) in high school.
  • Alcohol and marijuana-use trajectories were analyzed as predictors of social functioning, mental and physical health, and academic performance.


  • Higher alcohol and marijuana use was associated with greater delinquency, poorer academic performance and poorer physical/mental health in high school.
  • Researchers found differences in trajectories of use by ethnicity and race. For youth who used alcohol and marijuana at approximately the same level: Non-white youth reported poorer academic performance and physical health compared to white youth.
  • White youth appeared to experience less negative effects from both marijuana and alcohol use, yet they are at a higher risk for using marijuana and alcohol during middle and high school years.

According to study researchers, it’s important for parents and educations to talk to youth—especially non-white youth about alcohol and marijuana use from an early age. For one, preexisting factors that that weren’t included in the study, such as parental involvement, racial discrimination, or home environments, could have played a role in the teens’ alcohol and marijuana use.

Researchers suggest that young people need to better understand the consequences of marijuana (i.e. its potential effect on a developing brain and how it can potentially affect academic performance, according to study results).

Increasing protective factors (i.e. parental support, etc.) could possibly help, conclude study researchers.


Source for Today’s Article:

D’Amico, E. J., et al., “Alcohol and marijuana use trajectories in a diverse longitudinal sample of adolescents: examining use patterns from age 11 to 17 years,” Addiction, Version of Record online: Jun 14, 2016; doi: 10.1111/add.13442.