The COGA prospective study began data collection in 2004 and is ongoing. Details on data collection and procedures have been published previously.56 Briefly, offspring from families densely affected by alcohol use problems and comparison community families who were 12 to 22 years old at intake and who had at least 1 parent interviewed in an earlier phase of the COGA study were enrolled, with new subjects added as they reached 12 years of age. Subjects were interviewed every 2 years with a comprehensive battery that included the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA57), covering substance use problems and other psychiatric disorders and related behavior, personality questionnaires, family history of alcohol use problems, and a neurophysiologic battery. An age-appropriate SSAGA (cSSAGA58) was used for subjects younger than 18 years. At the time of analysis, this study presents data on 2,625 offspring from 2,413 nuclear families who had at least 1 follow-up interview; 1,931 participants had a third assessment, 1,324 a fourth assessment, 842 had a fifth assessment, 428 had a sixth assessment, and thus far 8 participants have had
