COGA is a multi-generational family-based study of genetic and environmental factors for alcohol use disorder and related traits, which ascertained alcohol-dependent probands and a smaller number of comparison families from six US sites (Begleiter, 1995; Dick et al. in press). The current work focused on the initial COGA sample of proband and control families (Phase 1 and Phase 2), as well as the COGA Prospective Study (Phase 4). For Phase 1 and Phase 2, probands from alcohol treatment centers and their families were invited to participate if the family had two or more members in the COGA catchment area. Comparison families were recruited from the same communities. Phase 4 examines how genetic and environmental risk unfolds across development among offspring of the initial COGA sample. Offspring between ages 12-22 with at least one parent who had previously completed an interview were assessed every two years (Bucholz et al. 2017; Dick et al. in press). The Institutional Review Boards at all data gathering sites approved this study, and written consent (and assent for adolescents) was obtained from all participants. Reports between
