Volumetric reductions in the subgenual anterior cingulate cortex in adolescents with bipolar I disorder

Abstract

Objectives: A range of prefrontal and subcortical volumetric abnormalities have been found in adults and adolescents with bipolar disorder. It is unclear, however, if these deficits are present early in the onset of mania or are a consequence of multiple mood episodes or prolonged exposure to medication. The goal of this study was to examine whether youth with bipolar I disorder who recently experienced their first episode of mania are characterized by brain volumetric abnormalities.

Methods: Anatomical images from magnetic resonance imaging of 26 13- to 18-year-old adolescents with bipolar I disorder and 24 age-comparable healthy controls with no personal or family history of psychopathology were analyzed using whole-brain voxel-based morphometry (VBM).

Results: Compared with healthy controls, adolescents with bipolar I disorder had significantly less gray matter volume in the left subgenual cingulate cortex [p<0.05, family-wise error (FWE)-corrected].

Conclusions: Adolescents with a recent single episode of mania have smaller subgenual cingulate cortex volume than do their healthy counterparts, suggesting that this anomaly occurs early in the onset of, or may predate the disorder. Longitudinal studies are needed to examine the impact of this volumetric reduction on the course and outcome of this disorder.

Fig. 1

Extracted mean subgenual anterior cingulate cortex (sACC) gray matter values in bipolar disorder (BD) and healthy comparison (HC) groups by voxel-based morphometry. FWE = family-wise error.

Fig. 2

Scatterplot of voxel-based morphometry (VBM) and manual tracing results across all subjects (Spearman’s correlation, R = 0.31, p = 0.03). FWE = family-wise error.

Fig. 3

/I> Adolescents with bipolar I disorder have smaller subgenual cingulate gray matter volume than do healthy adolescents on whole-brain analysis [results shown in red at a statistical threshold of p < 0.05, family-wise error (FWE)-corrected and superimposed on manually traced left and right subgenual cingulate cortices].