Participants came from the Collaborative Study on the Genetics of Alcoholism (COGA) Prospective Study. COGA is a diverse, multi-site, multi-generational family-based study of genetic and environmental factors for alcohol use disorders (Begleiter et al., 1995). Probands (individuals with alcohol dependence) were ascertained through alcohol treatment programs at seven sites in the United States. In addition, a group of non-ascertained comparison families were recruited from the same communities. Beginning in 2004, a sample of adolescent and young adult offspring (ages 12–22) of prior adult COGA participants were recruited into the COGA Prospective Study (Bucholz et al., 2017) to study the development of alcohol use disorders and related problems (Dick et al., 2014). Prospective Study participants were interviewed at enrollment and followed up at approximately biennial intervals. The Institutional Review Board at all sites approved this study, and written consent (and assent for adolescents) was obtained from all participants.
