The prospective component of the COGA study began in 2004 and is ongoing (35). Offspring from high risk and comparison families who are aged 12–22 (born 1982 or later) at intake, and who have at least one parent who was interviewed for the COGA study (1991–2005), are enrolled, with new subjects added as they reach the age of 12. Subjects are interviewed every two years with the SSAGA or, for subjects younger than 18, the childhood version (C-SSAGA), which covers alcohol and other substance use problems and disorder and other psychiatric disorders (36). This study focused on 3257 offspring from 1912 nuclear families with 1 (51.9%), 2 (31.8%) or 3 or more (16.3%) participating offspring as of June, 2016 who had data on both parents. The dataset included 2, 4, 6, 8 and 10 year follow-up data for 2851, 2337, 1812, and 1153 and 442 individuals, respectively. Sixty-four percent of the sample had 3 or more follow-up interviews, 16.4% had 2, 15.7% had 1, and 12.4% had not yet had a follow-up interview. Sample demographics are available in Table 1.
