Cortical gray matter deficit in patients with bipolar disorder

Background: cortical gray matter volume deficit and ventricular enlargement are well documented in schizophrenia, but their presence in bipolar disorder is less well established. Methods: global cortical gray matter, white matter and sulcal CSF, as well as lateral and third ventricular volume measures, were derived from axial MRI brain images obtained on age- matched bipolar (n=9), schizophrenic (n=9), and control (n=16) subjects. All subjects were free of history of alcohol or other substance dependence. Results: relative to controls, bipolar patients had widespread volume deficits of cortical gray matter but not of cortical white matter. Schizophrenic patients had an even more severe cortical gray matter deficit and greater sulcal and lateral ventricular enlargement than the bipolar patients. Conclusions: this group of patients with bipolar disorder had a widespread deficit of cortical gray matter similar to, but less pronounced than, that observed in patients with schizophrenia.