¹University of Sussex, Psychology, Sussex, United Kingdom, ²University of Portsmouth, Psychology, Portsmouth, United Kingdom, ³Macquarie University, Psychological Sciences, Sydney, Austria

Background: Coffee is amongst the most widely consumed beverages globally, with consumption largely driven by the post-ingestive effects of caffeine. Habitual caffeine consumption can result in dependence with withdrawal symptoms occurring when deprived. The Incentive Sensitization Theory of Addiction, proposes a dissociation between wanting and liking, where sensitisation of reward systems increases wanting without concurrent increase in liking. Few studies have investigated wanting and liking for coffee in habitual consumers with none controlling for deprivation, despite much evidence that caffeine reinforcement occurs largely by alleviating withdrawal. Additionally, no study has measured both explicit and implicit wanting and liking for coffee, where a truly motivational response is established for the latter.

Aims & Objectives: Therefore, this study aimed to investigate explicit and implicit wanting and liking for coffee in two groups: high (more than 2 cups a day) and low (less than one cup a day) consumers both acutely caffeine deprived and not deprived.

Method: Sixty-four healthy human volunteers, aged 18-45 (n = 32 per group) completed two test sessions, in which deprivation state was manipulated using caffeine or placebo. Participants first completed the Bond-Lader mood battery and an explicit wanting-liking measure for coffee and two fruit teas (lemon and ginger, and mint) using a taste test and online questionnaire. Participants then consumed a lemon and ginger tea containing either 100mg of caffeine or placebo administered double-blind. After 30-minutes, participants repeated mood and explicit measures followed by an implicit association task to measure implicit wanting and liking for coffee. A final mood assessment concluded each session. Mood analyses compared consumer groups across drug condition and rating times. Explicit wanting and liking were analysed across groups at baseline and post-drug (factoring in drug condition: caffeine or placebo) for each drink type. Implicit wanting and liking for coffee were contrasted between groups across rating types and drug conditions. Habitual caffeine consumption was controlled for throughout.

Results: Both consumer groups showed increased alertness from baseline at both post-drug timepoints, with a stronger caffeine-related increase in high than low consumers. Contentedness increased at both post-drug timepoints for both groups, while calmness increased at the first post-drug timepoint only. At baseline high consumers showed greater explicit wanting than liking for coffee compared to low consumers. No baseline wanting-liking differences were observed for either consumer group for either tea. Post-drug explicit wanting decreased more than liking for both consumer groups for lemon and ginger tea only. No wanting-liking differences emerged post-drug for coffee or mint tea for either consumer group across drug condition. Greater implicit wanting than liking was observed for both consumer groups across drug condition.

Discussion & Conclusions: These findings suggest that distinct underlying motivational processes may drive habitual coffee consumption. Although high consumers displayed explicit wanting-liking dissociation at baseline consistent with sensitisation theory, this did not persist post-drug, suggesting withdrawal alone may not fully account for the motivation to consume coffee. However, both groups showed greater implicit wanting than liking for coffee, indicating a motivational bias independent of consumption level or deprivation.