Trained interviewers obtained verbal consent prior to the start of the interview and completed the assessment – a modified for telephone administration version of the Semi-Structured Assessment for the Genetics of Alcoholism [SSAGA; (Bucholz et al., 1994)]. The SSAGA assessed the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [DSM-IV; (American Psychiatric, 1994)] substance use and other psychiatric disorders and related psychosocial domains. All data from waves 1, 3, 4, and 5 available were utilized and collapsed across waves for analytic purposes. In cases where age at first trauma exposure, age at onset of each stage of alcohol involvement, or age of other individual level covariates was reported in more than one interview, we used the age at first occurrence reported the first time the participant endorsed it.
