The present study included adolescents (aged 12–17) for whom the following apply: (1) had GWAS data available, (2) completed the adolescent version of the Semi-Structured Assessment for the Genetics of Alcoholism for Children Interview (Bucholz et al. 1994; Kuperman et al. 2013) during their baseline and first follow-up (approximately two years after the baseline) assessments, (3) were under age 18 at their first follow-up assessment, and (4) were of European or African ancestry as determined by genetic ancestry principal component analysis. This strategy resulted in an analytic sample of 1,200 adolescents (49.9% male) from 458 COGA extended families. Youth from both case and comparison families were included. Specifically, this analytic sample included 764 European (EA; Mage = 12.99, SD = 1.13 at baseline assessment; Mage = 15.05, SD = 1.23 at Time 2; 50.0% male) and 436 African (AA; Mage = 12.99, SD = 1.11 at baseline assessment; Mage = 15.11, SD = 1.23 at Time 2; 49.8% male) ancestry participants. No differences were observed between this analytic sample and the whole adolescent sample at baseline in externalizing behaviors. However,
