At T1 and T2, adolescents self-reported (0 = no; 1 = yes) the lifetime occurrence of alcohol consequences and dependence symptoms. We examined adolescent alcohol problems because research shows that genetic influences are stronger, and environmental influences weaker, on adolescents’ problematic alcohol use than on alcohol initiation [59]. Adolescents’ reports were used because parents are less accurate reporters of adolescent alcohol use [60] and because adolescents were the only informants who reported on symptoms at two waves. Eighteen consequences as a result of alcohol use (e.g., “did you miss school or work,” “did you have problems with family or friends”) and 21 alcohol dependence symptoms (e.g., “spent so much time arranging to get alcohol or having them on your mind so much that you had little time for anything else”) were summed at each wave to create separate T1 and T2 lifetime alcohol problem variables. T1 alcohol problems was a covariate predicting T2 alcohol problems for the prospective prediction. See Table 1 for descriptives.
