COGA recruited DSM-III-R and DSM-IV AD probands from inpatient and outpatient treatment facilities through six participating sites: State University of New York Downstate Medical Center, University of Connecticut Health Science Center, Indiana University School of Medicine, University of Iowa College of Medicine, University of California School of Medicine, and Washington University School of Medicine. Recruitment and assessment procedures, including a clinical interview, neurophysiological assessments and DNA collection have been described previously (Begleiter et al., 1995; Foroud et al., 2000). Probands and family members were administered the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), a poly-diagnostic interview (Bucholz et al. 1994; Hesselbrock et al. 1999). Individuals below the age of 18 were administered an adolescent version of the SSAGA. The laboratory and data-collection procedures were identical at each of the sites (Begleiter et al., 1998). Institutional review boards at all sites approved the study.
