title: Decreased interhemispheric resting-state functional connectivity in first-episode, drug-naive major depressive disorder.
abstract: BACKGROUND
  Major depressive disorder (MDD) is shown to have structural and functional abnormalities in specific brain areas and connections by recent neuroimaging studies. However, little is known about the alterations of the interhemispheric resting-state functional connectivity (FC) in patients with MDD. In the present study, we used a newly developed voxel-mirrored homotopic connectivity (VMHC) method to investigate the interhemispheric FC of the whole brain in patients with MDD at rest.
  
  
  METHODS
  Twenty-four first-episode, drug-naive patients with MDD and 24 age-, gender-, and education-matched healthy subjects underwent a resting-state functional magnetic resonance imaging (fMRI). An automated VMHC approach was used to analyze the data.
  
  
  RESULTS
  Patients with MDD showed lower VMHC than healthy subjects in the medial prefrontal cortex (MPFC) and the posterior cingulate cortex/precuneus (PCC/PCu), two core regions within default mode network (DMN). Both left and right MPFC showed reduced FC with the other frontal areas and with right anterior cingulate gyrus (ACC), while PCC/PCu exhibited abnormal FC with the frontal areas and thalamus in patient group. Significant positive correlation was observed between VMHC in MPFC and persistent error response of Wisconsin Card Sorting Test (WCST-Pre) in patients. Further ROC analysis revealed that VMHC in the MPFC and PCC/PCu could be used to differentiate the patients from healthy subjects with relatively high sensitivity and specificity.
  
  
  CONCLUSIONS
  Our results suggest that decreased VMHC in brain regions within DMN may underlie the pathogenesis of MDD.
authors.affiliation: Mental Health Center, the First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, China. guowenbin76@163.com
authors.forename: Wenbin
authors.initials: W
authors.lastname: Guo
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Yi
authors.initials: Y
authors.lastname: Dai
authors.forename: Muliang
authors.initials: M
authors.lastname: Jiang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Liuyu
authors.initials: L
authors.lastname: Yu
authors.forename: Liling
authors.initials: L
authors.lastname: Long
authors.forename: Huafu
authors.initials: H
authors.lastname: Chen
authors.forename: Qing
authors.initials: Q
authors.lastname: Gao
authors.forename: Changqing
authors.initials: C
authors.lastname: Xiao
mesh_terms: D000293:Adolescent; D000328:Adult; D054022:Cerebrum / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D030141:Feedback, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D012146:Rest / Q000502:physiology* / Q000523:psychology