The Collaborative Study on the Genetics of Alcoholism is a family pedigree investigation which enrolls treatment-seeking alcohol-dependent probands who meet the DSM-IV for alcohol dependence (18). Probands are recruited at six centers in the United States. The only exclusions are for life-threatening medical disorders, repeated intravenous drug use, and an inability to speak English. Comparison subjects have been identified from driver's license records, attendance at a dental clinic, random mailings, and other approaches (19). Written informed consent to participate in the study was obtained from all enrolees. Probands and their relatives were interviewed at baseline by using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), which focuses on demography, substance use patterns, and the assessment of 17 axis I DSM-IV diagnoses, as well as characteristics of bipolar disorder (20).
