EFFECTS OF HABITUAL CAFFEINE CONSUMPTION AND DEPRIVATION ON WANTING AND LIKING FOR CAFFEINATED DRINKS

This study investigated Incentive Sensitisation Theory (IST), measuring wanting and liking explicitly and implicitly for coffee (Experiment 1) and explicitly for other caffeinated drinks (Experiment 2) as a function of habitual caffeine consumption and deprivation in humans. In Experiment 1, 32 high (≥2 cups/day) and 32 low coffee consumers (<1 cup/day) completed two test sessions, in which deprivation state was manipulated double-blind using caffeine (100mg) or placebo consumed as a tea. At each session, participants completed the Bond-Lader mood battery and an explicit wanting-liking measure for coffee, the tea consumed and a control tea before and after manipulating deprivation. Implicit wanting and liking for coffee was measured following manipulating deprivation using an implicit association task. Experiment 2 was conducted online and recruited 441 volunteers. Participants rated explicit wanting and liking for a range of caffeinated and non-caffeinated drinks, and self-reported their mood, appetite, thirst, habitual caffeine consumption and time since last caffeine consumption. For Experiment 1, high coffee consumers showed greater explicit wanting than liking for coffee compared to low consumers at baseline and across time points, consistent with IST. However, there was no effect of caffeine deprivation. Greater implicit wanting than liking for coffee was observed for both groups, with no effect of deprivation. For Experiment 2, wanting and liking ratings correlated with habitual caffeine consumption for caffeinated but not non-caffeinated drinks, with no effect of caffeine deprivation. An absence of deprivation effects indicates that withdrawal relief alone may not fully explain the motivation to consume caffeinated drinks.