Dissociation Pattern in Default-Mode Network Homogeneity in Drug-Naive Bipolar Disorder.

Sujuan Li,Sara Arenas De Leon,Hui Xiang,Hui Tang,Lu Wang,Wenbin Guo,Chujun Wu,Kun Jin,Haishan Wu,Pan Pan,Bolun Wang,Yan Qiu,Jindong Chen,Jing Huang,Ziwei Teng

doi:10.3389/fpsyt.2021.699292

Abstract

Default mode network (DMN) plays a key role in the pathophysiology of in bipolar disorder (BD). However, the homogeneity of this network in BD is still poorly understood. This study aimed to investigate abnormalities in the NH of the DMN at rest and the correlation between the NH of DMN and clinical variables in patients with BD. Forty drug-naive patients with BD and thirty-seven healthy control subjects participated in the study. Network homogeneity (NH) and independent component analysis (ICA) methods were used for data analysis. Support vector machines (SVM) method was used to analyze NH in different brain regions. Compared with healthy controls, significantly increased NH in the left superior medial prefrontal cortex (MPFC) and decreased NH in the right posterior cingulate cortex (PCC) and bilateral precuneus were found in patients with BD. NH in the right PCC was positively correlated with the verbal fluency test and verbal function total scores. NH in the left superior MPFC was negatively correlated with triglyceride (TG). NH in the right PCC was positively correlated with TG but negatively correlated with high-density lipoprotein cholesterol (HDL-C). NH in the bilateral precuneus was positively correlated with cholesterol and low-density lipoprotein cholesterol (LDL-C). In addition, NH in the left superior MPFC showed high sensitivity (80.00%), specificity (71.43%), and accuracy (75.61%) in the SVM results. These findings contribute new evidence of the participation of the altered NH of the DMN in the pathophysiology of BD.

Highlights

Bipolar disorder (BD) is a severe mental disorder, mainly characterized by repeated episodes of depression and mania
The abnormalities are mainly concentrated in the default mode network (DMN) that comprises a set of brain regions including posterior cingulate gyrus (PCC), precuneus, medial prefrontal cortex (MPFC), bilateral angular gyri (AG), lateral temporal cortex (LTC), and hippocampi [3, 4]
Clinical symptoms of BD were assessed with the Hamilton Depression Rating Scale-17 (HAMD-17) [25], the Young Mania Rating Scale (YMRS) [26] and the Hamilton Anxiety Scale14 (HAMA-14) [27]

Summary

Introduction

Bipolar disorder (BD) is a severe mental disorder, mainly characterized by repeated episodes of depression and mania. Depending on its manic level, BD can be further categorized into two types: BD type I (with typical manic episodes) or BD type II (with mild manic episodes) [1]. Abnormal functional connections in certain brain areas of patients with BD have been shown with functional magnetic resonance imaging (fMRI) [2]. The abnormalities are mainly concentrated in the default mode network (DMN) that comprises a set of brain regions including posterior cingulate gyrus (PCC), precuneus, medial prefrontal cortex (MPFC), bilateral angular gyri (AG), lateral temporal cortex (LTC), and hippocampi [3, 4]. Evidence has shown that DMN plays a crucial role in the pathophysiology of BD [4, 5].

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