Depression in schizophrenia: II. MRI and PET findings

Background: Despite consistent descriptions of depressive symptoms in schizophrenia, little is known about their neurobiology. The purpose of this study was to examine the association of depression in schizophrenia with measures of brain anatomy and metabolism. Methods: Seventy-nine patients were grouped according to their ratings on the Hamilton Depression Rating Scale (HDRS): ≥ 18 was the cutoff between the “high” and “low” depression groups. All patients underwent clinical and magnetic resonance imaging (MRI) evaluation, and a subsample of 37 underwent 2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) measurements of cerebral glucose metabolism. Results: The high depression group had larger bilateral temporal lobe volumes and decreased laterality (left minus right of metabolism in the anterior cingulate). Conclusions: The neurobiology of depression in schizophrenia thus seems to share features with major depression due to other disease states.