Brain Imaging in Antisocial Personality: II

This is the second in a series of posts looking at recent imaging findings in antisocial personality.  In the first post, I reviewed an fMRI study that found deficits in connectivity maturation involving the premotor cortex in a sample of incarcerated juveniles.

In this post, I will review a study looking a emotional face processing.  Accurately assessing the emotions of others and adjusting ones own behavior is a key component to social development and appropriate social behavior.

Individuals with antisocial personality disorder commonly display childhood and adolescent forms of the disorder.  These child and adolescent behaviors often meet the criteria for conduct disorder.  About 75% of children with conduct disorder will go on to develop adult antisocial personality disorder.

Passamonti and colleagues from the University of Cambridge in England recently completed and published a study of emotional face processing in a series of male adolescents with conduct disorder and control adolescents without conduct disorder.

Conduct disorder adolescents were divided into those with an earlier age of onset (at least one significant conduct disorder symptoms prior to age 10) and those whose first significant symptom developed at 10 or later.  This classification is considered valid as adolescents with later emerging conduct disorder problems are felt to be more influenced by peer group behaviors.

Subjects completed a series of face emotion tasks while being imaged using functional magnetic resonance imaging.  Emotional images presented fell into one of three emotions--angry faces, sad faces or a neutral facial expression.

The key findings from the study related to amygdala responses were:

• Both groups of adolescents with conduct disorder demonstrated a reduced responses in brain regions felt to be linked to antisocial behavior
• Early onset conduct disorder adolescents showed reduced amygdala activation for sad versus neutral faces
• Early onset conduct disorder adolescents showed reduced amygdala activation for sad faces relative to the control fixation task

The conduct disorder groups also demonstrated abnormal responses to facial emotions in ventromedial prefrontal cortex, orbitofrontal cortex and the insula. 

The authors note their study provides some support for the distinction between early and late onset conduct disorder.  Although these groups share some features in emotional processing, early onset conduct disorder appears to be associated with more severe deficits in accurately processing sad faces.

This study suggests emotional processing deficits may contribute to some of the behaviors of antisocial personality.  Such individuals are typically seen to lack empathy and to behave without regard for the effect of their behavior on others.  Part of this pattern may be a reduced ability to recognize emotional expression in others.  A part of their behavior may represent a partial "blindness" to sad emotional states of those around them including family members and peers.

The authors note their study my provide a impetus to describing a phenotype with a poor prognosis and likely continuation of antisocial behavior into adulthood.  Functional MRI studies of neural markers may aid in defining high-risk groups for more intensive secondary prevention intervention.

Photo of great blue heron at sunrise in South Padre Island, Texas from the author's files.

Passamonti L, Fairchild G, Goodyer IM, Hurford G, Hagan CC, Rowe JB, & Calder AJ (2010). Neural abnormalities in early-onset and adolescence-onset conduct disorder. Archives of general psychiatry, 67 (7), 729-38 PMID: 20603454