Voxel-based morphometry was used to analyze structural MRI scans from 23 boys with callous-unemotional conduct problems (mean age 11 yrs 8 months) and 25 healthy controls, in a study at the Institute of Psychiatry, King’s College, London, UK, and other centers in London and Germany. Both grey matter volume and concentration were examined, controlling for cognitive ability and ADHD. Boys with unemotional conduct problems showed increased grey matter concentration in the medial orbito-frontal and anterior cingulate cortices, and increased grey matter volume and concentration in the temporal lobes bilaterally and the cerebellum. The findings were consistent with a delay in cortical maturation in cortical areas involved in decision making, morality and empathy in boys with callous-unemotional conduct problems. 
COMMENT. Contrary to previous reports of decreased concentration and volume of cortical areas in psychopathic adolescents and adults with conduct disorders, this study found increases in grey matter concentration in orbito-frontal cortex and anterior cingulate cortex in 11-year-old patients. Blair RJR, of the National Institute of Mental Health, Bethesda, MD, in an editorial, remarks on the advances in the science of a neural substrate for lack of emotion, and in driving callous behavior in boys with conduct problems. The progress is not only in tolerance for the field of neurobiology of anti-social behavior but also its sophistication . Children with callous-unemotional traits have an increased risk for anti-social behavior. A better understanding of the cause should lessen the stigma and facilitate appropriate treatment. Children with ADHD complicated by unemotional conduct disorders should receive psychiatric care to lessen the risk of anti-social behavior.