Different spatial patterns of brain atrophy and global functional connectivity impairments in major depressive disorder

Chuanjun Zhuo,Jiajia Zhu,Chunli Wang,Xiaolei Ma,Hongru Qu,Wen Qin

doi:10.1007/s11682-016-9645-z

Abstract

Alterations in grey matter structure and functional connectivity (FC) are pathological features of major depressive disorder (MDD). However, the relationship between brain structural and functional impairments in MDD remains uncertain. Thus, the aim of this study was to investigate the relationship between alterations in grey matter volume (GMV) and resting-state global functional connectivity density (rs-gFCD) in MDD. Forty-five patients with MDD and 48 healthy controls underwent structural and resting-state functional magnetic resonance imaging (fMRI). GMV and rs-gFCD maps of each subject were created, and the intergroup differences in these neuroimaging metrics were evaluated. Compared to healthy controls, patients with MDD displayed reduced GMV in the left insula, putamen, amygdala and hippocampus (mainly in the limbic system). In contrast, decreased rs-gFCD was observed in the left postcentral and precentral gyri, right fusiform gyrus and lingual gyrus (mainly in the sensory system). Furthermore, we found no significant correlations between GMV and rs-gFCD in these brain regions. Finally, overlap ratio analysis demonstrated that the spatial distribution patterns of intergroup differences on the GMV and rs-gFCD maps were distinct. Our findings suggest that the presence of distinct spatial distribution patterns of brain atrophy and global FC impairments might be pathological features of MDD.

Highlights

Major depressive disorder (MDD) is typically characterized by pervasive and persistent sadness and feelings of helplessness and worthlessness (American Psychiatric Association 2013; Kahn 1975)
MDD patients showed significantly decreased resting-state global functional connectivity density (rs-gFCD) in the left postcentral and precentral gyri, which are ascribed to the sensorimotor system, and decreased rs-gFCD in the right fusiform and lingual gyri, which are ascribed to the visual system (Fig. 2)
Despite no significant inter-group difference, we found a trend towards a significant reduction in grey matter volume (GMV) (Fig. S2) (P < 0.06, family-wise error (FWE) corrected) in the left insula, putamen, amygdala and hippocampus, the spatial extent was smaller than those in the parametric statistics

Summary

Introduction

Major depressive disorder (MDD) is typically characterized by pervasive and persistent sadness and feelings of helplessness and worthlessness (American Psychiatric Association 2013; Kahn 1975). In the last ten years, due to advances in neuroimaging techniques, many studies using magnetic resonance imaging (MRI) have explored the pathological features of MDD in terms of both structural and functional alterations in the brain. These studies have provided many key findings that have enhanced our understanding of the neurobiology of depression (Northoff et al 2011; Phillips et al 2015; Savitz and Drevets 2009; Wise et al 2014). To the best of our knowledge, few studies have investigated the relationships between the spatial distribution patterns of GMV and FC alterations

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