Resting-State Synchrony in Long-Term Abstinent Alcoholics

Background Alcohol dependence is a disorder with an impulsive and compulsive drive toward alcohol consumption and an inability to inhibit alcohol consumption. Neuroimaging studies suggest that these behavioral components correspond to an increased involvement of regions that mediate appetitive drive and reduced involvement of regions that mediate executive control within top-down networks. Little is known, however, about whether these characteristics are present after long periods of abstinence. Methods Resting-state functional magnetic resonance imaging data were collected to examine resting-state synchrony (RSS) differences between 23 long-term abstinent alcoholics (LTAA; 8 women, age: M = 48.46, SD = 7.10), and 23 nonsubstance abusing controls (NSAC; 8 women, age: M = 47.99, SD = 6.70). Using seed-based measures, we examined RSS with the nucleus accumbens (NAcc) and the subgenual anterior cingulate cortex (sgACC). All participants were assessed with the intra/extradimensional set shift task outside of the scanner to explore the relationship between RSS and cognitive flexibility. Results Compared to NSAC, LTAA showed (i) decreased synchrony of limbic reward regions (e.g., caudate and thalamus) with both the anterior cingulate cortex seed and the NAcc seed and (ii) increased synchrony of executive control regions (e.g., dorsolateral prefrontal cortex) with both the NAcc seed and the sgACC seed. RSS differences were significantly correlated with task performance. Conclusions The results are consistent with an interpretation of an ongoing compensatory mechanism in LTAA evident during rest, in which decision-making networks show reduced synchrony with appetitive drive regions and increased synchrony with inhibitory control regions. In addition, RSS differences were associated with cognitive flexibility. These resting-state findings indicate an adaptive mechanism present in long-term abstinence that may facilitate the behavioral control required to maintain abstinence.