Alcohol dependent probands were ascertained through alcohol treatment programs and evaluated at seven centers in the United States: Indiana University, State University of New York Health Science Center Brooklyn, University of Connecticut, University of Iowa, University of California/San Diego, Washington University/St. Louis and Howard University as part of the Collaborative Study on the Genetics of Alcoholism (Begleiter et al., 1995; Edenberg, 2002; Foroud et al., 2000; Reich et al., 1998). The institutional review boards of all participating institutions approved the study. After providing informed consent, the probands and their relatives were administered a validated poly-diagnostic instrument, the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) (Bucholz et al., 1994; Hesselbrock et al., 1999), which allows assessment of alcohol dependence under several diagnostic systems. Details of the ascertainment and assessment have previously been published (Begleiter et al., 1995; Foroud et al., 2000; Reich et al., 1998) and are available at zork.wustl.edu/niaaa/coga_instruments/resources.html.
