title: Decreased insular connectivity in drug-naive major depressive disorder at rest.
abstract: BACKGROUND
  The insula has extensive links to the fronto-limbic circuit and associated regions, which is involved in the neurobiology of major depressive disorder (MDD). However, few studies are designed to examine the insular connectivity in MDD. This study was performed to examine the insular connectivity in drug-naive MDD directly by using the insular cortices as seeds.
  
  
  METHODS
  Functional magnetic resonance imaging data were obtained from 44 drug-naive MDD patients and 44 healthy controls at rest. The functional connectivity (FC) method was used to analyze the images.
  
  
  RESULTS
  Significantly decreased FCs were found between the right insula and the left middle frontal gyrus (MFG, orbital part), left superior temporal gyrus (STG), right putamen, and right middle occipital gyrus (MOG), and between the left insula and the left superior temporal pole and right MOG in the patients compared with the controls. There were significantly negative correlations between the z values of the left insula-left superior temporal pole connectivity and the current episode duration (r=-0.332, p=0.028), between the z values of the right insula-left STG connectivity and the episode number (r=-0.343, p=0.023), and between the z values of the right insula-left MFG (orbital part) connectivity and the Automatic Thoughts Questionnaire scores (r=-0.359, p=0.017) in the patients.
  
  
  CONCLUSIONS
  The findings reveal that depressed patients have decreased insular connectivity with the fronto-limbic circuit, hate circuit, and visual regions, and suggest that the insula may act as an integration center of emotional processing which is disrupted in the depressed patients.
authors.affiliation: Mental Health Center, the First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi, China. Electronic address: guowenbin76@163.com.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Guo
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: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Mental Health Center, the First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi, China.
authors.forename: Changqing
authors.initials: C
authors.lastname: Xiao
authors.affiliation: Mental Health Center, the First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi, China.
authors.forename: Zhikun
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Mental Health Center, the First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi, China.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Liu
authors.affiliation: Mental Health Center, the First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi, China.
authors.forename: Miaoyu
authors.initials: M
authors.lastname: Yu
authors.affiliation: Mental Health Center, the First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Mental Health Institute of the Second Xiangya Hospital, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha 410011, Hunan, China.
authors.forename: Jingping
authors.initials: J
authors.lastname: Zhao
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000503:physiopathology*; D004644:Emotions; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology; D009778:Occipital Lobe / Q000503:physiopathology*; D011699:Putamen / Q000503:physiopathology*; D012146:Rest; D013702:Temporal Lobe / Q000503:physiopathology*; D055815:Young Adult
keywords: Fronto-limbic circuit; Functional connectivity; Hate circuit; Insula; Major depressive disorder