Blunted autonomic responses to emotional stimuli in alcoholism: relevance of impulsivity

Alcohol dependence is associated with abnormalities in the processing of emotional signals and impulsive alcohol-seeking behaviours, and these alterations compromise the effectiveness of treatment approaches. However, there is a lack of studies linking the experience of emotions to everyday motivationally relevant stimuli in alcohol-dependent individuals using both autonomic and self-report measures. We analysed heart rate (HR), skin conductance (SC) and subjective emotional reactivity to everyday affective stimuli in alcohol-dependent individuals, and their associations with impulsivity and degree of alcohol consumption. SC and HR were continuously monitored in 28 alcohol-dependent individuals and in 31 non-alcohol healthy controls during passive viewing of pleasant, unpleasant, and neutral emotional pictures. Participants assessed the pictures for valence, arousal, and dominance and completed the Barratt Impulsiveness Scale. Alcohol-dependent individuals showed reduced HR and SC reactivity to both positive and negative emotional stimuli. In the case of SC, this blunted response was associated with impulsivity. Furthermore, alcohol-dependents displayed decoupled physiological and subjective responses, with blunted autonomic responses and normal subjective reports regarding emotional stimuli. Our findings indicate that alcohol-dependent individuals failed to use emotional autonomic feedback in response to natural, emotionally relevant stimuli, and provide initial evidence of the contribution of impulsivity to emotional processing deficits in this population. These results are in keeping with the proposed key role played by emotional experience and impulsivity in substance abuse.