Marijuana use and academic performance: A longitudinal study
Wednesday, November 6, 2013
: 1:10 p.m. - 1:30 p.m.
Background: Marijuana is a popular illicit drug among adolescents and its impact on academic performance has been widely debated. The objectives of this study are to: 1) describe distinct trajectories of marijuana use in a cohort of adolescents evaluated annually from Grade 6-12 (2003-2009), and 2) examine the association among trajectories, study skills, and high school completion. Methods: The sample consisted of a cohort of 619 randomly-selected students (52% males; 48% White, 36% Black, 12% Latino). Every spring, students reported their 30-day frequency of marijuana use, and teachers rated study skills. Schools provided dropout data. We used semi-parametric group based modeling to identify trajectories and mixed effects models to examine the association of marijuana trajectories and study skills. Results: From Grade 6-12, marijuana prevalence increased from 2.3% to 18.6%. Adolescents followed three distinct marijuana use trajectories: Abstainer (78%), Increasing-Low (12%), and Increasing-High (10%). The Increasing-High and Increasing-Low groups had significantly higher dropout rates (28% and 33%) than Abstainers (14%). Teachers rated the study skills of the two marijuana-using groups significantly lower than abstainers, even in sixth grade. Conclusion: The majority of adolescents consistently abstained from using marijuana throughout middle and high school. However, a significant proportion of youth followed increasing trajectories of marijuana use and had higher dropout rates and worse study skills. Interestingly, low study skills preceded marijuana use and did not worsen as marijuana use increased. Thus, we cannot conclude that marijuana use led to the poor academic outcomes, but they may have shared risk factors.
Public health or related education
Public health or related research
Social and behavioral sciences
Describe the prevalence of marijuana use among adolescents from Grade 6 to Grade 12 in Georgia.
Differentiate the distinct developmental trajectories of marijuana use among adolescents.
Discuss the association between marijuana use trajectories, teacher rated study skills and dropout in middle and high school.
Keyword(s): Marijuana, Adolescents
Presenting author's disclosure statement:
Qualified on the content I am responsible for because: I have been working as a Research Assistant for three years on a longitudinal study examining the different levels of risk and protective factors that influence the developmental trajectories of children and young adolescents from middle to high school in relation to drug and alcohol use, school dropout, aggression toward peers, delinquency, dating violence, weapon carrying, suicide thoughts and attempts. Among my research interests are modeling of developmental trajectories of substance use behaviors among adolescents.
Any relevant financial relationships? No
I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines,
and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed
in my presentation.