Participants came from the Collaborative Study on the Genetics of Alcoholism (COGA), a diverse, family-based study whose objective is to identify genetic variants associated with AUD and related disorders (Begleiter et al., 1995; Bucholz et al., 2017; Reich et al., 1998). Probands were identified through alcohol treatment centers across seven sites in the United States. Probands along with their families were invited to participate if the family was sufficiently large (usually sibships greater than 3, with parents available), and had two or more members in the COGA catchment area. Comparison families were recruited from the same communities. The Institutional Review Board at all data collection sites approved the study, and written consent was obtained from all participants.
