title: Abnormal functional connectivity density in first-episode, drug-naive adult patients with major depressive disorder.
abstract: Previous studies have found evidence of brain functional connectivity (FC) changes with pre-selected region-of-interest (ROI) method in major depressive disorder (MDD). However, these studies could not completely exclude personal inequality when drawing ROIs manually and did not measure the total number of FC for each voxel. Here, we firstly applied functional connectivity density (FCD) mapping, a voxel-based analysis to locate the hubs with amount changes of FC between 22 first-episode, drug-naive adult MDD patients and 22 healthy control (HC) subjects. Both short-range (local) FCD and long-range (distal) FCD were measured. The relationships of FCD changes with Hamilton Depression Rating Scale (HAMD) scores and illness duration were also explored. Compared with the HC group, MDD patients showed significantly decreased short-range FCD in the left superior temporal gyrus (STG), the right orbital frontal cortex (OFC) and bilateral precuneus, while significantly decreased long-range FCD was found in bilateral middle occipital gyrus (MOG), superior occipital gyrus (SOG) and right calcarine. These results firstly demonstrated both local and distal alterations of connection amount at voxel level, and highlighted that the OFC, the precuneus, the STG and the visual cortex were important brain network hubs for first-episode, drug-naive adult MDD patients. Our findings were complementary for previous structural and functional studies in MDD patients, and provided new evidence of the dysfunction of connection hubs in the pathophysiology of MDD at voxel level.
authors.affiliation: Neurobiological Laboratory, West China Hospital of Sichuan University, Chengdu, Sichuan, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Zou
authors.affiliation: School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Long
authors.affiliation: School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.affiliation: Department of Orthopedic Surgery, West China Hospital of Sichuan University, Chengdu, Sichuan, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Sun
authors.affiliation: Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan, China. Electronic address: chenhf@uestc.edu.cn.
authors.forename: Huafu
authors.initials: H
authors.lastname: Chen
authors.affiliation: Mental Health Center, West China Hospital of Sichuan University, Chengdu, Sichuan, China. Electronic address: sunxl58@163.com.
authors.forename: Xueli
authors.initials: X
authors.lastname: Sun
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000503:physiopathology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000503:physiopathology; D010296:Parietal Lobe / Q000503:physiopathology; D013702:Temporal Lobe / Q000503:physiopathology; D014793:Visual Cortex / Q000503:physiopathology
keywords: Drug naïve; First-episode; Functional connectivity density; Hub; Major depressive disorder; Resting-state fMRI