Regional cortical thickness recovery with extended abstinence after treatment in those with alcohol use disorder.

Several cross-sectional investigations reported widespread cortical thinning in those with alcohol use disorder (AUD). The few longitudinal studies investigating cortical thickness changes during abstinence are limited to the first month of sobriety. Consequently, cortical thickness changes during extended abstinence in those with AUD is unclear. In this study, AUD participants were studied at approximately 1 week (n=68), 1 month (n=88) and 7.3 months (n=40) of abstinence. Forty-five never-smoking controls (CON) completed a baseline study, and 15 were reassessed after approximately 9.6 months. Participants completed magnetic resonance imaging studies at 1.5T and cortical thickness for 34 bilateral regions of interest (ROI) was quantitated with FreeSurfer. AUD demonstrated significant linear thickness increases in 25/34 ROI over 7.3 months of abstinence. The rate of change from 1 week to 1 month was greater than 1 month to 7.3 months in 19/34 ROIs. Proatherogenic conditions were associated with lower thickness recovery in anterior frontal, inferior parietal and lateral/mesial temporal regions. After 7.3 months of abstinence, AUD were statistically equivalent to CON on cortical thickness in 24/34 ROIs; the cortical thickness differences between AUD and CON in the banks superior temporal gyrus, post central, posterior cingulate, superior parietal, supramarginal and superior frontal cortices were driven by thinner cortices in AUD with proatherogenic conditions relative to CON. In actively smoking AUD, increasing pack-years was associated with decreasing thickness recovery primarily in the anterior frontal ROIs. Widespread bilateral linear cortical thickness recovery over 7.3 months of abstinence was the central finding for this AUD cohort. Proatherogenic conditions were associated with decreased thickness recovery and thinner cortex after 7.3 months of abstinence in several ROIs; this suggests alterations in perfusion or vascular integrity may relate to structural recovery in AUD. These results support the adaptive and beneficial effects of sustained sobriety on brain structural recovery in those with AUD.