Decreased N-acetylaspartate in children with familial bipolar disorder

Relatively low levels of brain N-acetylaspartate, as measured by magnetic resonance spectroscopy, may indicate decreased neuronal density or viability. Dorsolateral prefrontal levels of N-acetylaspartate have been reported to be decreased in adults with bipolar disorder. We used proton magnetic resonance spectroscopy to investigate dorsolateral prefrontal N-acetylaspartate levels in children with familial bipolar disorder.

Subjects were 15 children and adolescents with bipolar disorder, who each had at least one parent with bipolar disorder, and 11 healthy controls. Mean age was 12.6 years for subjects and controls. Subjects were allowed to continue current medications. Proton magnetic resonance spectroscopy at 3-Tesla was used to study 8 cm(3) voxels placed in left and right dorsolateral prefrontal cortex.

Bipolar subjects had lower N-acetylaspartate/Creatine ratios only in the right dorsolateral prefrontal cortex (p <.02). No differences in myoinositol or choline levels were found.

Children and adolescents with bipolar disorder may have decreased dorsolateral prefrontal N-acetylaspartate, similar to adults with BD, indicating a common neuropathophysiology. Longitudinal studies of at-risk children before the onset and during the early course of bipolar disorder are needed to determine the role of prefrontal N-acetylaspartate as a possible risk marker and/or indication of early bipolar illness progression.