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.

Inclusion Criteria:

- Very light or moderate consumer of caffeine (either daily or non-daily).

- Social drinker of alcohol.

- Has experience in lifetime of heavy alcohol consumption.

- Read, write, and speak English fluently.

Exclusion Criteria:

- Serious and unstable illnesses including current hepatic, renal, gastroenterologic,
respiratory, cardiovascular (including ischemic heart disease, uncontrolled
hypertension, and congestive heart failure), endocrinologic, neurologic (including
stroke, transient ischemic attack, subarachnoidal bleeding, brain tumor,
encephalopathy, and meningitis), or hematologic disease.

- Parkinson's disease, seizure disorder, or history of significant head trauma.

- Current psychiatric illness

- Pregnant or nursing women or women who are not using an effective means of birth
control.