Adult Outcomes Associated with Adolescent Alcohol and Marijuana Use

Importance: The comparative outcomes of adolescent marijuana and alcohol use are unknown. Understanding long-term outcomes associated with adolescent substance use is critical for informed policy decisions regarding marijuana considering that public perceptions of marijuana harm are decreasing and efforts to legalize and decriminalize marijuana are growing.

Objective: To determine and compare outcomes in young adulthood associated with alcohol and marijuana use across adolescence.

Design: A cohort of children originally recruited as part of a randomized intervention trial in 1st
grade followed to age 25.

Setting: The study began in nine public schools (27 classrooms) in Baltimore City in the fall of
1993.

Participants: 678 predominantly African American children (age 6) and families were originally recruited to participate in the intervention trial.  The sample for these analyses focus on the 608 children who participated over time (53.2% male).  The majority of the sample (63.4%) received free or reduced price lunch in first grade.

Exposures: Longitudinal patterning of alcohol and marijuana use from grades 8-12, estimated through latent profile analysis, was the primary independent variable of interest.

Main Outcome Measures: The outcomes for this analysis focus on nine outcomes measured in adulthood (ages 19-25), including indicators of drug dependence, mental health, socioeconomic status, criminal justice system involvement, and risky sexual behavior.

Results:  Findings show negative outcomes of alcohol and marijuana use over adolescence. Compared to the non-use class, use classes had higher rates of risky sexual behavior, Antisocial Personality Disorder, and high school dropout.  Comparing the two classes with similar alcohol but different marijuana patterns, the marijuana use class was more likely to have a criminal justice record and meet criteria for drug dependence.

Conclusions and Relevance:  Findings suggests that adult outcomes associated with marijuana among urban youth are broad and relatively comparative to those of alcohol with the exception of meeting criteria for drug dependence and for having a criminal justice record, which are greater for marijuana.  State policies commercializing marijuana need to carefully consider how best to restrict access to marijuana and use of marijuana by vulnerable youth since negative consequences are likely.  This presentation will provide insight on potential policies based on successes with youth smoking, which has known negative effects.