A large body of research suggests that individuals are accurate at subjectively judging
their own alcohol intoxication when assessed relative to blood alcohol concentration. Although
caffeine’s ability to antagonize alcohol-induced intoxication is generally regarded as a myth, it is
often consumed with alcohol in preparation for tasks such as driving. Currently, however, few
studies have directly examined the effect of caffeine consumption on subjective alcohol
intoxication.
The purpose of the present study was to investigate the interaction of alcohol and caffeine
on subjective intoxication. A screening survey was used to recruit light to moderate drinking
males between the ages of 21 and 30 years of age. The subjective effects of alcohol (water,
placebo, .04 and .08) with eight ounces of coffee (0, or 2.0 mg/kg caffeine) were measure in 133
subjects. Subjectively, a cup of caffeinated coffee increased perceptions of intoxication for .04-
alcohol condition, but did not effect perceived intoxication in other conditions
