Abnormal Voxel-Based Degree Centrality in Patients With Postpartum Depression: A Resting-State Functional Magnetic Resonance Imaging Study

Abstract

Postpartum depression (PPD) is a major public health concern with significant consequences for mothers, their children, and their families. However, less is known about its underlying neuropathological mechanisms. The voxel-based degree centrality (DC) analysis approach provides a new perspective for exploring the intrinsic dysconnectivity pattern of whole-brain functional networks of PPD. Twenty-nine patients with PPD and thirty healthy postpartum women were enrolled and received resting-state functional magnetic resonance imaging (fMRI) scans in the fourth week after delivery. DC image, clinical symptom correlation, and seed-based functional connectivity (FC) analyses were performed to reveal the abnormalities of the whole-brain functional network in PPD. Compared with healthy controls (HCs), patients with PPD exhibited significantly increased DC in the right hippocampus (HIP.R) and left inferior frontal orbital gyrus (ORBinf.L). The receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of the above two brain regions is all over 0.7. In the seed-based FC analyses, the PPD showed significantly decreased FC between the HIP.R and right middle frontal gyrus (MFG.R), between the HIP.R and left median cingulate and paracingulate gyri (DCG.L), and between the ORBinf.L and the left fusiform (FFG.L) compared with HCs. The PPD showed significantly increased FC between the ORBinf.L and the right superior frontal gyrus, medial (SFGmed.R) compared with HCs. Mean FC between the HIP.R and DCG.L positively correlated with EDPS scores in the PPD group. This study provided evidence of aberrant DC and FC within brain regions in patients with PPD, which was associated with the default mode network (DMN) and limbic system (LIN). Identification of these above-altered brain areas may help physicians to better understand neural circuitry dysfunction in PPD.

Keywords: fMRI; postpartum depression; receiver operating characteristic (ROC) curve analysis; seed-based functional connectivity; voxel-based degree centrality.

FIGURE 1

Comparisons of degree centrality between patients with postpartum depression (PPD) and healthy controls (HCs). (A) Brain regions with different degree centrality (DC) values between groups: HIP.R and ORBinf.L. (B,C) The distribution and comparison of DC values of brain regions in the PPD and HCs. (D,E) The ROC curve evaluates the diagnostic value of the DC value of different brain regions to distinguish patients with PPD from healthy mothers. HIP.R, right hippocampus; ORBinf.L, left inferior frontal orbital gyrus.

FIGURE 2

(A) Brain regions showing aberrant functional connectivity (FC) with HIP.R (seed region) in the PPD group compared with the HCs. Cool color represents significantly decreased FC. (B,C) Mean values of the abnormal functional connectivity in these groups. (D,E) The ROC curve evaluates the diagnostic value of the FC value of different brain regions to distinguish patients with PPD from healthy mothers, in which HIP.R was as seeds. (F) Scatter plots depicting a partial correlation between the HIP.R-related functional connectivity in the DCG.L and the EDPS scores for patients with PPD. (G) Brain regions showing aberrant FC with ORBinf.L (seed region) in the PPD group compared with the HCs. Warm color represents significantly increased FC, and cool color represents significantly decreased FC. (H,I) Mean values of the abnormal functional connectivity in these groups. (J,K) The ROC curve evaluates the diagnostic value of the FC value of different brain regions to distinguish patients with PPD from healthy mothers, in which ORBinf.L was as seeds. HIP.R, right hippocampus; ORBinf.L, left inferior frontal orbital gyrus; MFG.R, right middle frontal gyrus; DCG.L, left median cingulate and paracingulate gyri; FFG.L, left fusiform; SFGmed.R, right superior frontal gyrus, medial. ***Significant at 0.001 level and *significant at 0.05 level.