Affective traits of psychopathy are linked to white-matter abnormalities in impulsive male offenders

Objective: 

Psychopathy is a personality disorder typified by lack of empathy and impulsive antisocial behavior. Psychopathic traits may partly relate to disrupted connections between brain regions. The aim of the present study was to link abnormalities in microstuctural integrity of white-matter tracts to the severity of different psychopathic traits in 15 male offenders with impulse control problems and 10 without impulse control problems. 

Method: 

Psychopathic traits were assessed using the Psychopathy Checklist-revised (PCL-R). Diffusion-weighted MRI was used to examine white-matter tracts. Fractional anisotropy (FA), an index of white-matter integrity, was calculated for each voxel. Clusters of voxels showing a significant relationship with psychopathy severity were submitted to probabilistic tractography. 

Results: 

No significant correlations between psychopathy severity and FA were present in the whole group of impulsive and nonimpulsive offenders. In impulsive offenders. interpersonal-affective traits (PCL-R Factor I) were negatively correlated with FA in the anterior and posterior temporal lobe and orbitofrontal area. Further analyses indicated that elevated affective traits (PCL-R Facet 2) were specifically related to reduced FA in the right temporal lobe. 

Conclusions: 

Our findings suggest that white-matter abnormalities in temporal and frontotemporal tracts may be linked to the interpersonal-affective deficits of psychopathy in offenders with relatively severe impulse control problems. Our study offers novel insights into the relationships between the four facets of psychopathy and disrupted structural connectivity, and may provide new leads for further characterization of different subtypes of antisocial populations.