Structural abnormalities in major depressive and bipolar disorders

January 01, 0001

Structural abnormalities in major depressive and bipolar disorders

The purpose of this study by UK authors was to investigate structural brain changes in major depressive disorder (MDD) and bipolar disorder (BD) using meta-analysis of primary studies; assess the effects of medication, demographic, and clinical variables; and compare the findings with those of a meta-analysis of studies on BD. They included 225 studies that used magnetic resonance imaging or x-ray computed tomography to compare brain structure in patients with MDD with that of controls were included in an online database, and 143 that measured common brain structures were selected for meta-analysis.

They found: "Compared with the structure of a healthy brain, MDD was associated with lateral ventricle enlargement; larger cerebrospinal fluid volume; and smaller volumes of the basal ganglia, thalamus, hippocampus, frontal lobe, orbitofrontal cortex, and gyrus rectus. Patients during depressive episodes had significantly smaller hippocampal volume than patients during remission. Compared with BD patients, those with MDD had reduced rates of deep white matter hyperintensities, increased corpus callosum cross- sectional area, and smaller hippocampus and basal ganglia. Both disorders were associated with increased lateral ventricle volume and increased rates of subcortical gray matter hyperintensities compared with healthy controls."

They authors concluded: "The meta-analyses revealed structural brain abnormalities in MDD that are distinct from those observed in BD. These findings may aid investigators attempting to discriminate mood disorders using structural magnetic resonance imaging data."

Perhaps down the road brain imaging will be part of routine diagnostic process for patients with these disorders.

For the full abstract, click here.

Arch Gen Psychiatry 68(7):675-690, July 2011 © 2011 to the American Medical Association
Structural Neuroimaging Studies in Major Depressive Disorder: Meta-analysis and Comparison With Bipolar Disorder. Matthew J. Kempton, Zainab Salvador, Marcus R. Munafò, et al. Correspondence to Dr. Kempton: [email protected]

Category: P. Psychological. Keywords: major depressive disorder, bipolar disorder, magnetic resonance imaging, computed tomography, meta-analysis of observational studies, journal watch.
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 22 July 2011

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.