The families used in the analyses are taken from multiplex families recruited from alcoholic probands who were in alcohol or other substance dependence treatment facilities. All probands met DSM-IIIR criteria for alcohol dependence and Feighner definite criteria (COGA criteria). In addition to the probands, the study required two additional first-degree relatives who were alcohol dependent by the same COGA criteria on direct interview (in person). Semi-Structured Assessment for the Genetics of Alcoholism, SSAGA, a polydiagnostic instrument designed by COGA with well established reliability (Bucholz and others 1994) and validity (Hesselbrock and others 1999), was administered in person to determine psychiatric diagnoses in all family members. All subjects completed a neuropsychological battery and family history questionnaire, and EEGs/ERPs were recorded.
