title: Altered brain network modules induce helplessness in major depressive disorder.
abstract: OBJECTIVE
  The abnormal brain functional connectivity (FC) has been assumed to be a pathophysiological aspect of major depressive disorder (MDD). However, it is poorly understood, regarding the underlying patterns of global FC network and their relationships with the clinical characteristics of MDD.
  
  
  METHODS
  Resting-state functional magnetic resonance imaging data were acquired from 16 first episode, medication-naïve MDD patients and 16 healthy control subjects. The global FC network was constructed using 90 brain regions. The global topological patterns, e.g., small-worldness and modularity, and their relationships with depressive characteristics were investigated. Furthermore, the participant coefficient and module degree of MDD patients were measured to reflect the regional roles in module network, and the impairment of FC was examined by network based statistic.
  
  
  RESULTS
  Small-world property was not altered in MDD. However, MDD patients exhibited 5 atypically reorganized modules compared to the controls. A positive relationship was also found among MDD patients between the intra-module I and helplessness factor evaluated via the Hamilton Depression Scale. Specifically, eight regions exhibited the abnormal participant coefficient or module degree, e.g., left superior orbital frontal cortex and right amygdala. The decreased FC was identified among the sub-network of 24 brain regions, e.g., frontal cortex, supplementary motor area, amygdala, thalamus, and hippocampus.
  
  
  CONCLUSIONS
  The limited size of MDD samples precluded meaningful study of distinct clinical characteristics in relation to aberrant FC.
  
  
  CONCLUSIONS
  The results revealed altered patterns of brain module network at the global level in MDD patients, which might contribute to the feelings of helplessness.
authors.affiliation: Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wanping South Road, Shanghai 200030, PR China; Department of Radiology and BRIC, University of North Carolina, 130 Mason Farm Road, Chapel Hill, NC 27599-7513, USA.
authors.forename: Daihui
authors.initials: D
authors.lastname: Peng
authors.affiliation: Department of Radiology and BRIC, University of North Carolina, 130 Mason Farm Road, Chapel Hill, NC 27599-7513, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Shi
authors.affiliation: Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wanping South Road, Shanghai 200030, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Shen
authors.affiliation: Department of Radiology and BRIC, University of North Carolina, 130 Mason Farm Road, Chapel Hill, NC 27599-7513, USA.
authors.forename: Ziwen
authors.initials: Z
authors.lastname: Peng
authors.affiliation: Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wanping South Road, Shanghai 200030, PR China.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wanping South Road, Shanghai 200030, PR China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Liu
authors.affiliation: Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wanping South Road, Shanghai 200030, PR China.
authors.forename: Meihui
authors.initials: M
authors.lastname: Qiu
authors.affiliation: Department of Medical Imaging, the Fifth People׳s Hospital of Shanghai, Shanghai, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Huashan Hospital, Fudan University, Shanghai, PR China.
authors.forename: Kaida
authors.initials: K
authors.lastname: Jiang
authors.affiliation: Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wanping South Road, Shanghai 200030, PR China. Electronic address: yirufang@gmail.com.
authors.forename: Yiru
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Department of Radiology and BRIC, University of North Carolina, 130 Mason Farm Road, Chapel Hill, NC 27599-7513, USA; Department of Brain and Cognitive Engineering, Korea University, Seoul, Korea. Electronic address: dgshen@med.unc.edu.
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000473:pathology / Q000503:physiopathology / Q000523:psychology*; D004644:Emotions; D005260:Female; D006380:Helplessness, Learned; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012107:Research Design
keywords: Functional connectivity; Helplessness; Major depressive disorder; Modularity; Small-worldness