Gray matter asymmetry in the orbitofrontal cortex in relation to psychopathic traits in adolescents

Abstract

Background: Structural abnormalities in the orbitofrontal cortex (OFC) of incarcerated psychopaths have been well documented. However, the neural correlates of psychopathic traits in younger and nonclinical samples remain poorly understood.

Aim: The present study aimed to examine the structural brain asymmetry in the OFC in relation to dimensions of psychopathic traits in adolescents from the community.

Method: In 29 youths from the community, childhood psychopathic traits including narcissism, impulsivity, and callous-unemotional traits were assessed when they were 7- to 10 years old (Time 1), and their gray matter (GM) volumes were measured using structural Magnetic Resonance Imaging when they were 10- to 14 years old (Time 2).

Results: After controlling for age, sex, IQ, pubertal stage, and whole-brain volumes, callous-unemotional traits were associated with right-left asymmetry in the medial OFC (mOFC), that is, smaller right mOFC GM as compared to the left. Impulsivity was associated with left-right asymmetry in the mOFC, that is, smaller left mOFC than the right. Narcissism was not associated with any GM asymmetry measure. No significant association was found for the lateral OFC, amygdala, caudate and putamen.

Conclusion: The present findings provide further support that dimensions of psychopathic traits may have distinct neurobiological correlates.

Keywords: Adolescents; Brain imaging; Gray matter asymmetry; Orbitofrontal cortex; Psychopathy.