Common Grey Matter Reductions in Alcohol Use and Obsessive-Compulsive Disorders: A Metanalysis

Abstract Background Though compulsive drinking is a hallmark of alcohol use disorder (AUD), little is known of the neural mechanisms driving this behavior. To further the understanding of the neural underpinnings of this compulsivity, a metanalytic approach was used to examine grey matter (GM) volume differences related to AUD, and contrast these differences with GM volume differences in obsessive-compulsive disorder (OCD), to find common underlying regional brain differences. Methods We systematically meta-analyzed case-control studies investigating GM volume that used whole brain voxel-based morphometry separately for AUD and OCD, and then the results of both were directly compared. The Seed-based d Mapping (SDM) software was used to perform the metanalyses. Results The AUD metanalysis used 19 citations, with 736 AUD and 827 control individuals. The OCD metanalysis had 25 citations with 995 OCD and 1177 control individuals. The AUD group showed decreased GM in areas including frontal, limbic, temporal and cerebellar regions. The OCD group had decreased GM in frontal and insular regions but increases in the hypothalamus and brainstem. Importantly, the main outcome showed both groups had decreased GM overlapping in the anterior cingulate and insula. Brain regions were p Conclusions Common brain regional differences in the anterior cingulate and insula that overlap between AUD and OCD suggest that interventions targeting these regions could prove to be beneficial in treating compulsive drinking related to AUD. Further research into the functional role of these brain regions in the etiology of compulsive drinking in AUD is warranted.