Males between the ages of 18 and 25 years were recruited using a combination of venue-based method and a respondent-driven procedure that has been described elsewhere [42]. Telephone screening with research staff was used to complete a questionnaire [43-44] which was used to select individuals who met eligibility for the study. All participants signed informed consent, and the study was approved by The Scripps Research Institute Internal Review Board. Participants were excluded from further evaluation if they met diagnostic criteria for alcohol or other substance dependence, or other major Axis I psychiatric disorders according to criteria outlined in the Third Diagnostic and Statistical Manual Disorders (DSM-III-R) [45]. Participants were also excluded from this study if they were taking prescribed medication, had any major medical condition as described previously [42, 46-47]. Participants were instructed not to use alcohol or any other drugs for 3 days prior to testing. Records from 38 of the participants were still available on readable media and were used in the present analyses. EEG/ERP and ERO responses to alcohol challenge in these participants have been reported previously [42, 46-47]. Data in the present report included only ERO responses to placebo, for comparison to the periadolescent sample.
