Brain responses to anticipating and receiving beer: Comparing light, at-risk, and dependent alcohol users

Abstract

Impaired brain processing of alcohol-related rewards has been suggested to play a central role in alcohol use disorder. Yet, evidence remains inconsistent and mainly originates from studies in which participants passively observe alcohol cues or taste alcohol. Here, we designed a protocol in which beer consumption was predicted by incentive cues and contingent on instrumental action closer to real life situations. We predicted that anticipating and receiving beer (compared with water) would elicit activity in the brain reward network and that this activity would correlate with drinking level across participants. The sample consisted of 150 beer-drinking males, aged 18 to 25 years. Three groups were defined based on alcohol use disorders identification test (AUDIT) scores: light drinkers (n = 39), at-risk drinkers (n = 64), and dependent drinkers (n = 47). fMRI measures were obtained while participants engaged in the beer incentive delay task involving beer- and water-predicting cues followed by real sips of beer or water. During anticipation, outcome notification and delivery of beer compared with water, higher activity was found in a reward-related brain network including the dorsal medial prefrontal cortex, orbitofrontal cortex, and amygdala. Yet, no activity was observed in the striatum, and no differences were found between the groups. Our results reveal that anticipating, obtaining, and tasting beer activates parts of the brain reward network, but that these brain responses do not differentiate between different drinking levels.

Keywords: alcohol; brain; reward.