Gray matter volume differences in impulse control and addictive disorders

Abstract

BACKGROUNDS: The concepts of addictions and impulse control disorders are changing as reflected in the 11thversion of International Classification of Disorders (ICD-11, WHO, 2018). However, studies focusing on direct comparison of structural brain differences in behavioral and substance addictions are limited.AIM: Here we contrast gray matter volumes (GMVs) across groups of individuals with compulsive sexual behaviordisorder (CSBD), gambling disorder (GD), and alcohol use disorder (AUD) with those with none of these disorders(healthy controls participants; HCs).METHODS: Voxel-based morphometry (VBM) was employed to study brain structure and severities of addictions symptoms were assessed with questionnaires. To identify brain regions related to severities of addictions,correlations between questionnaires scores and GMVs were computed.MAIN OUTCOME: We collected MRI (GMVs) data from 26 CSBD patients, 26 GD patients, 21 AUD patients and25 HC participants (all heterosexual males; age: 24-60; M = 34.5, SD = 6.48).RESULTS: Affected individuals (CSBD, GD, AUD) compared to HC participants showed smaller GMVs in the leftfrontal pole, specifically in the orbitofrontal cortex. The most pronounced differences were observed in the GD andAUD groups, and the least in the CSBD group. There was a negative correlation between GMVs and disorderseverity in the CSBD group. Higher severity of CSBD symptoms was correlated with decreased GMV in the rightanterior cingulate gyrus.CLINICAL IMPLICATIONS: Our findings suggest similarities between specific impulse control disorders andaddictions.STRENGHS AND LIMITIATIONS:This study is the first showing smaller GMVs in 3 clinical groups of CSBD, GD and AUD. But the study was limitedonly to heterosexual men. Longitudinal studies should examine the extent to which ventral prefrontal decrements in volume may represent preexisting vulnerability factors or whether they may develop with disorder progression.CONCLUSIONS: Our research extends prior findings in substance use disorders of lower GMV in prefrontalcortical volumes among 3 clinical groups of patients with specific impulse control and behavioral and substanceaddictive disorders. The negative correlation between GMVs and CSBD symptoms and right anterior cingulate gyrus suggests a link with clinical symptomatology.