Limbic hyperactivation during processing of neutral facial expressions in children with bipolar disorder.

Reflecting a paradigm shift in clinical neuroscience, many chronic psychiatric illnesses are now hypothesized to result from perturbed neural development. However, most work in this area focuses on schizophrenia. Here, we extend this paradigm to pediatric bipolar disorder (BD), thus demonstrating traction in the developmental psychobiology perspective. To study amygdala dysfunction, we examined neural mechanisms mediating face processing in 22 youths (mean age 14.21 +/- 3.11 yr) with BD and 21 controls of comparable age, gender, and IQ. Event-related functional MRI compared neural activation when attention was directed to emotional aspects of faces (hostility, subjects' fearfulness) vs. nonemotional aspects (nose width). Compared with controls, patients perceived greater hostility in neutral faces and reported more fear when viewing them. Also, compared with controls, patients had greater activation in the left amygdala, accumbens, putamen, and ventral prefrontal cortex when rating face hostility, and greater activation in the left amygdala and bilateral accumbens when rating their fear of the face. There were no between-group behavioral or neural differences in the nonemotional conditions. Results implicate deficient emotion-attention interactions in the pathophysiology of BD in youth and suggest that developmental psychobiology approaches to chronic mental illness have broad applicability.