Voxel-based morphometry analysis of structural brain scans in skin-picking disorder

Abstract

BackgroundSkin-picking disorder (SPD) is characterized by the excessive and repetitive manipulation of one's own skin resulting in tissue damage and impaired social functioning. There are only a few studies with small sample sizes that examined possible brain abnormalities in SPD, which is classified as a syndrome related to obsessive-compulsive disorders (OCD). MethodThe current voxel-based morphometry (VBM) study compared data from 35 SPD patients and 35 control participants including both genders (mean age = 35 years, SD = 15). In addition, patients' self-reports on symptom severity, duration and impairment were correlated with grey matter volumes (GMV) in regions of interest (basal ganglia, orbitofrontal cortex (OFC), insula). ResultsRelative to controls, the patients showed reduced GMV in the OFC and in the insula. Basal ganglia volume did not differ between the groups. Within the SPD group, disorder-related impairment and symptom duration were negatively correlated with GMV in basal ganglia regions. DiscussionThis study indicated that SPD patients show GMV abnormalities in regions concerned with interoception (insula) and reinforcement of behavior (OFC). Whether the correlational findings are disorder-specific or reflect secondary processes needs to be investigated in a future longitudinal study with additional clinical control groups.