The sample consisted of 1,601 participants (800 males and 801 females) between 17 and 25 years of age from the prospective sample of the COGA study. The participants were offspring from families ascertained in previous phases of COGA (Begleiter et al., 1995; Edenberg et al., 2005): (1) multiplex alcohol dependent families (AD), many with multiple alcoholism-affected family members, and (2) community comparison families (CC) drawn from the general population. Participants enter the study when they are between the ages of 12–22 and are reassessed every two years with age-appropriate clinical, behavioral and neurophysiological assessments. For additional details of the sample characteristics, see Dick et al. (2013). For this study, participants within the age range of 17–25 years were selected; each individual was represented only once in the sample, at their earliest assessment within this age range. The number of subjects in each subgroup is shown in Table 1. The sample predominantly included participants with European ancestry (EA: 65.08%) and African ancestry (AA: 32.29), in addition to a small fraction with Hispanic ancestry (HA: 2.62%). Data from six collection centers have
