Participants were 635 unrelated individuals who had participated in the Study of Addiction: Genetics and the Environment (SAGE; Bierut et al., under review; http://zork.wustl.edu/gei/). Participants in the current research were a subset of the SAGE sample, all of whom were drawn from a primary study of alcohol dependence (COGA; Reich et al., 1998) because these individuals had completed the Sensation Seeking Scale (Zuckerman, 1978; Zuckerman, 1996). Written informed consent was obtained from all participants following thorough description of the study. The average age of our sample was 45.3 years (with a range of 22 to 77), 55.1% were female, 65.2% met criteria for a lifetime DSM-IV alcohol dependence diagnosis, and 18.9% and 8.2% self-reported African and/or Hispanic ancestry, respectively.
