Psychology

Bipolar disorder

Orbitofrontal cortex

Economics

Major depressive disorder

White matter

Voxel-based morphometry

Depression (economics)

Bipolar I disorder

Functional connectivity

Central nervous system

Limbic system

Voxel

Neuroscience

Prefrontal cortex

Macroeconomics

Superior frontal gyrus

Anterior cingulate cortex

Magnetic resonance imaging

Functional magnetic resonance imaging

Cognition

Mania

Internal medicine

Radiology

Resting state fMRI

Amygdala

Neuroimaging

Medicine

NeuroImage Clinical

Major depressive disorder (MDD) and bipolar disorder (BD) are common severe affective diseases. Although previous neuroimaging studies have investigated brain abnormalities in MDD or BD, the structural and functional differences between these two disorders remain unclear. In this study, we adopted a multimodal approach, combining voxel-based morphometry (VBM) and functional connectivity (FC), to study the common and distinct structural and functional alterations in unmedicated MDD and BD patients. The VBM analysis revealed that both the MDD and BD patients showed decreased gray matter volume (GMV) in the left anterior cingulate cortex (ACC_L) and right hippocampus (HIP_R) compared with the healthy controls, and the MDD patients showed decreased GMV in the left superior frontal gyrus (SFG_L) and ACC_L compared with the BD patients. Furthermore, we took these clusters as seed regions to analyze the abnormal resting-state functional connectivity (RSFC) in the patients. We found that both the MDD and BD groups had decreased RSFC between the ACC_L and the left orbitofrontal cortex (OFC_L) and that the MDD group had decreased RSFC between the SFG_L and the HIP_L, compared with the healthy controls. Our results revealed that the MDD and BD patients were more similar than different in GMV and RSFC. These findings indicate that investigating the frontal-limbic system could be useful for understanding the underlying mechanisms of these two disorders.

Common and distinct abnormal frontal-limbic system structural and functional patterns in patients with major depression and bipolar disorder