Differentiating Heavy from Light Drinkers by Neural Responses to Visual Alcohol Cues and Other Motivational Stimuli

The course to alcohol dependence often starts with a preclinical period of heavy drinking. The present article reports functional magnetic resonance imaging data showing that even this pattern of alcohol consumption is associated with maladaptive neural responses to alcohol and other stimuli. When participants were confronted with visual cues related to alcohol, heavy drinkers showed amplified blood oxygen level-dependent signal responses in specific emotional areas (insular cortex) and in parts of the brain's reward circuitry (ventral striatum). This neuronal amplification was not present in light drinkers. Crucially, at the same time heavy drinkers showed reduced responses in frontal areas to pictures related to higher order life goals and in the cingulate cortex to appetitive food stimuli, suggesting that they have difficulty finding alternative, socially desirable goals. Using discriminant function analysis, we demonstrate that the combination of alcohol-related overactivation and underactivation to alternative goals allows heavy and light drinkers to be differentiated with a high degree of precision. Our findings highlight the diagnostic value of functional brain mapping of cue reactivity. Imaging measures may help to identify addictive dispositions in preclinical stages and to clarify the mechanisms that underlie the development and maintenance of alcohol dependence.