Summary of Study on Effects of Caffeine and Alcohol

According to the article, "Does Caffeine Counteract Alcohol-Induced Impairment?
The Ironic Effects of Expectancy*", a study was conducted by the Department of Psychology at the University of Kentucky to test the psychomotor performance when combining alcohol and caffeine. This means that they were trying to determine whether or not caffeine increased the effects of alcohol on motor skills or if a person believes it will have an impact it will simply because their mind believes it.

The participants were led to expect either that caffeine would increase alcohol-induced impairment or that it would have no effect. The hypothesis stated that if the participant believed the caffeine would increase the alcohol impairment, then they would show greater alcohol impairment than the participants who expected that the caffeine would not have an effect. This task was accomplished by some groups receiving a dose of caffeine and alcohol and other groups were given alcohol and a placebo caffeine. Along with the statement mentioned above, some groups were led to believe that the caffeine would further increase the impairing effect of alcohol and others were led to expect no effect.

After all participants were given their particular substances, they were monitored over a three hour period.

The results of the study were parallel to the hypothesis. The groups led to expect that the caffeine would have a more impairing effect on the alcohol showed greater impairment than those that had no indication of the effects of caffeine on alcohol.

This study suggests that a person who combines caffeine with alcohol and expects to have increased impairment or the ability to party longer, will get those effects.

Fillmore, Mark T., Emily L. Roach, and Julietta T. Rice. "Does Caffeine Counteract Alcohol-Induced Impairment?" Journal of Studies on Alcohol 63 (2002): 745-754. 23 Mar. 2008.