Data were analyzed in a cross sectional sample (N = 2938) of subjects who were assessed at least once when they were between the ages of 12 and 25 years. They were drawn from multiplex (densely affected) alcoholic families (recruited through a proband in treatment) and a set of community (comparison) families in the Collaborative Studies on Genetics of Alcoholism (COGA). Written informed consent was obtained from all subjects, and the Institutional Review Boards (IRB) of each collaborative site approved all procedures. The procedures used by COGA for diagnostic interviews and recording and analyzing EEG data have been described previously (Begleiter et al., 1995; Reich, 1996; Begleiter et al., 1998; Edenberg et al., 2005). A detailed description of population characteristics of alcohol use and dependence are given in section 2.6.
