Participant screening was initially conducted by a phone interview assessing alcohol use/dependence, use/dependence of other drugs, medical history, and mental health history. All participants were fully informed of the study's procedures and aims, and signed consent forms prior to participation. NAC subjects were asked to abstain from consuming alcohol for at least 24 h prior to any laboratory visit. A breathalyzer test (Intoximeters, Inc., St. Louis, MO) was administered, and a blood alcohol concentration of 0.000 was required of all participants in all sessions. A rapid screen test (Oral Fluid Drug Screen, Innovacon, San Diego, CA) was administered to all participants, and a negative result was required. Participants were compensated for their time and travel expenses upon completion of each session – $40 for each session and reimbursement for public transportation costs or mileage. Participants who completed the entire study were also given a $40 completion bonus. The compensation amounts and schedule were the same for all of the participants included in the current report.
