Co-occurrence of depressive symptoms and conduct problems conveys elevated risk for polysubstance use among adolescents: Results from national surveys

Early initiation of substance use is one of the strongest predictors of developing a substance use disorder in adulthood. Despite this risk, substance use among American adolescents remains common: 37% of American 8th graders have used alcohol in their lifetimes, 21% have smoked cigarettes, and 16% have used marijuana. Youth who use one substance are likely to use multiple substances. Polysubstance use is especially problematic during adolescence, conferring elevated risk for a number of adverse health behaviors, including risky sexual behavior, addiction, and suicidality. The current study characterizes the risk for adolescent polysubstance use associated with depressive symptoms (DS) and conduct problems (CP). Method Using a nationally representative US sample of 257,273 8th, 10th, and 12th grade students from Monitoring the Future surveys, logistic regression is used to estimate the odds of polysubstance (alcohol, marijuana, and cigarettes) use by adolescents with high levels of DS, CP, or both. Results DS and CP, alone and in combination, were associated with drastically elevated odds polysubstance use. Having high levels of both DS and CP was related to the highest odds of polysubstance use, increasing the risk by 38 times (OR=38.8, 95% CI=34.5-45.0). Notably, this risk was significantly higher among girls than boys. Conclusions Depressive symptoms and conduct problems are associated with heightened risk for polysubstance use among adolescents, particularly when high levels of both symptom categories are present. Prevention efforts for substance use should target both depressive symptoms and conduct problems in order to reduce the odds of polysubstance use among adolescents.