Long-term Associations Between Substance Use-Related Media Exposure, Descriptive Norms, and Alcohol Use from Adolescence to Young Adulthood.

Adolescents and young adults in the United States are constantly exposed to substance-related media and advertising content. The current study seeks to explore, developmentally, how exposure to substance-related media content influences both normative beliefs about peer alcohol use and individual alcohol use. Youth (N = 4'840; 50.6% female) were followed for ten years from age 12 to 22. Auto-regressive latent trajectory with structured residual (ALT-SR) models were used to explore within-person reciprocal associations between substance-related media content, descriptive norms, and alcohol use. Results indicated that' across adolescence and young adulthood, exposure to substance-related media content was associated with increased alcohol use via perceived alcohol norms. The pathway from media exposure to alcohol use was mediated by increased perceived norms for adolescents only. With screen time increasing over the last decade, it is important to invest resources into real-time interventions that address substance-related social media content as it relates to misperceived norms and to begin these interventions in early adolescence.