EFFECTS OF CAFFEINE DEPRIVATION ON TASTE AND MOOD

Despite its ubiquitous consumption in the natural environment, caffein e has not been a reliable reinforcer in laboratory settings. The reinf orcing effects of caffeine are greater in caffeine-dependent subjects relative to non-dependent subjects, but the mechanism underlying this difference remains unclear. We hypothesized that deprivation from caff eine would produce alterations in subjective ratings of stimuli common ly associated with caffeine consumption. Specifically, we hypothesized that hedonic ratings of the coffee taste would be selectively enhance d following caffeine deprivation. Twelve regular caffeine users receiv ed acute doses of caffeine (300 mg) or placebo after 33 h of caffeine deprivation or non-deprivation. They rated the taste of coffee and suc rose, saccharin, and quinine solutions on intensity, bitterness, sweet ness, pleasantness, and unpleasantness. Contrary to our hypothesis, su bjects' ratings of the pleasantness of the coffee taste were not signi ficantly altered by caffeine deprivation. However, subjects' ratings o f the bitterness and sweetness of the coffee taste and ratings of the sucrose solution were altered by caffeine. Implications of these data for caffeine self-administration are discussed.