Combined Effects of Alcohol and Caffeine

The purpose of this study is to examine the effects of caffeine on alcohol self-administration. Volunteers will participate in 7 experimental sessions in which they will be given the opportunity to self-administer an alcohol + caffeine or alcohol + caffeine-placebo beverage. The first 6 sessions will involve exposure to the two beverage conditions in mixed order three times each (e.g., A, B, B, A, A, B). The seventh session will be a choice session in which the participant will make a single choice at the beginning of the session about which beverage they will consume that day. In addition to the primary outcomes of quantity of alcohol self-administered and beverage choice, three additional outcomes will be measured including: 1). indirect measures of reinforcing effects (e.g. subjective ratings of liking, well-being, take again); 2). an alcohol-sensitive behavioral measure; and 3). participant ratings of degree of behavioral impairment.