Right anterior cingulate: a neuroanatomical correlate of aggression and defiance in boys.

Variation in emotional processes may contribute to aggressive and defiant behavior. This study assessed these problem behaviors in a large sample of children and adolescents in relation to the volume of two cortical regions with prominent roles in emotion processing, the anterior cingulate cortex (ACC) and ventromedial prefrontal cortex (vmPFC). One hundred seventeen participants (61 boys, 56 girls), ages 7-17, were recruited from the community. Aggressive and defiant behavior was measured using the parent- and teacher-reported Pediatric Behavior Scale and volumetric measures were generated using structural MRI. Regression analyses indicated a significant sex X ACC volume interaction in predicting aggressive and defiant behavior, without significant results for the vmPFC. Follow-up analyses showed that aggressive and defiant behavior is associated with decreased right ACC volume in boys and a nonsignificant reduction in left ACC volume in girls. These results are consistent with the notion that the right ACC acts as a neuroanatomical correlate of aggression and defiance in boys. The authors discuss this finding in light of its implications for understanding the neural correlates of antisocial behavior.