Potential participants first met individually with research staff to have the study explained and give written informed consent. During a screening period, participants had blood pressure and pulse taken, took an alcohol breathalyzer test to assess blood alcohol concentration, and completed a questionnaire that was used to gather information on demographics, personal medical history, ethnicity, and substance use history (Schuckit 1985). No individuals with detectable blood alcohol levels were included in the study dataset. During the screening period, the study coordinator noted whether the participant was agitated, tremulous, or diaphoretic.
