White matter metabolism differentiates schizophrenia and bipolar disorder: a preliminary PET study

Abstract Fluorodeoxyglucose-F18 positron emission tomography studies (FDG-PET) have shown similar corticolimbic metabolic dysregulation in bipolar disorder and schizophrenia, with hypoactive prefrontal cortex coupled with hyperactive anterior limbic areas. However, it is not clear whether white matter metabolism connecting these regions is differently affected in the two disorders. Twenty-six patients with schizophrenia (mean age±S.D.=30.23±9.7 year-old; 19 males; mean weight±S.D.=71±3kg) and 26 patients with bipolar disorder (mean age±S.D.=48.73±13 year-old; 18 males; mean weight±S.D.=75±15kg) underwent an FDG-PET scan. Normalized datasets the two groups of patients were compared on a voxel-by-voxel basis using a two-sample t statistic test as implemented in SPM8, and adding age as covariate. Group differences were assessed applying a threshold of p