Witnessing substance use increases same-day antisocial behavior among at-risk adolescents: Gene-environment interaction in a 30-day ecological momentary assessment study.

Many young adolescents are embedded in neighborhoods, schools, and homes where alcohol and drugs are frequently used. However, little is known about (a) how witnessing others' substance use affects adolescents in their daily lives and (b) which adolescents will be most affected. The current study used ecological momentary assessment with 151 young adolescents (ages 11-15) to examine the daily association between witnessing substance use and antisocial behavior across 38 consecutive days. Results from multilevel logistic regression models indicated that adolescents were more likely to engage in antisocial behavior on days when they witnessed others using substances, an association that held when substance use was witnessed inside the home as well as outside the home (e.g., at school or in their neighborhoods). A significant Gene × Environment interaction suggested that the same-day association between witnessing substance use and antisocial behavior was significantly stronger among adolescents with, versus without, the dopamine receptor D4 seven repeat (DRD4-7R) allele. The implications of the findings for theory and research related to adolescent antisocial behavior are discussed.