Study participants were enrolled in the Collaborative Study on the Genetics of Alcoholism (COGA), a large, multi-center, family study designed to identify genes that contribute to alcohol use disorders in high-risk (defined as recruited through alcohol dependent probands) and community comparison families (Begleiter et al., 1995). Since 2005, the adolescent and young adult study in COGA has used a longitudinal design to examine the development of alcohol use disorders in young participants from these families. Individuals aged 12 to 22 were recruited from six sites across the US and interviewed every two years. Institutional review boards at all sites approved the study design. Adult participants provided informed consent, parents provided consent for all children younger than 18, and children provided assent.
