Increased Subgenual Cingulate Cortex Volume in Pediatric Bipolar Disorder Associated with Mood Stabilizer Exposure

Objective: The subgenual cingulate (SGC) cortex has been implicated in the pathophysiology of mood disorders. We sought to study morphometric characteristics of the SGC in pediatric subjects with familial bipolar disorder (BD) compared with healthy controls. Method: Twenty children and adolescents with BD (mean age = 14.6 years, 4 females) and 20 healthy age-, gender-, and intelligence quotient-matched controls underwent high-resolution anatomical magnetic resonance imaging. Patients were primarily euthymic and most were taking medications. SGC cortex volumes were determined by manual tracings from a reliable rater, blinded to diagnosis. Analyses of covariance were performed with total cerebral gray matter and age as covariates. Results: No differences were found in SGC volumes between BD subjects and healthy controls. Further analysis revealed that BD subjects with past mood stabilizer exposure had significantly increased SGC volumes compared with BD subjects without mood stabilizer exposure, and compared with controls. The increase was driven by larger bilateral posterior SGC volumes. Conclusions: Youth with familial BD do not appear to have abnormalities in SGC volume. Mood stabilizer exposure, however, may be correlated with increases in SGC volume.