Recruitment employed local media and internet advertisements and word-of-mouth referrals. Initial inclusion criteria were: age 21–35 years, weight 110–210 pounds, good general health, not pregnant or lactating, no current or past major medical or psychiatric disorders including DSM-IV alcohol and substance dependence (other than nicotine), and no current use of any psychotropic medications. Participants were included if they met criteria for either a high or low-risk drinker. This distinction was defined by a predominant adult pattern of drinking (and minimally for the past two years). High-risk, heavy drinkers reported weekly binge drinking of ≥5 drinks for men, ≥4 for women, and regular consumption of 10–40 drinks per week. Low-risk, light drinkers reported rare/no binges and regular consumption of 1–5 drinks per week. These criteria were based upon established high- and low-risk drinking guidelines (20,21) and were consistent with prior studies (22–25). Candidates underwent medical and psychiatric screening to determine eligibility for an alcohol challenge (for details, see Suppl. Methods).
