A longitudinal study on the relationship between screen time and adolescent alcohol use: The mediating role of social norms.

It has been proposed that increased screen time contributes to increasing rates of adolescents abstaining from alcohol use. We argue that this proposition depends on the extent to which a type of screen time promotes social norms. We examined whether social norms mediated the association between alcohol use and i) social media, ii) television, and iii) video gaming.Multilevel models distinguishing between two time-varying factors: between-person effects and within-person effects. We used data from a randomized-controlled trial examining the efficiency of a personality-targeted substance use programme.3612 adolescents (47% female, mean age = 12.7, SD = 0.5 years) were recruited from 31 schools in the Greater Montreal area.We estimated the association between three types of screen time (social media, television, and video gaming), alcohol-related social norms, and alcohol use.Social norms mediated the association between social media use and alcohol use at both the between-person (β = 0.09, 95% CI = 0.08, 0.11, p = .000) and within-person level (β = 0.02, 95% CI = 0.01, 0.03, p = .000) and association between television use and alcohol use at the within-person level (β = 0.01, 95% CI = -0.004, 0.01, p = .000). Social norms did not mediate the association between video gaming and alcohol use.Alcohol-related social norms were shown to mediate the association between social media use, both at a correlational and longitudinal level, and the association between alcohol use and television use and alcohol use, at a longitudinal level, which may imply that these promote positive social norms towards alcohol use, subsequently increasing adolescents' drinking behaviour.