title: Morphologic and functional connectivity alterations of corticostriatal and default mode network in treatment-naïve patients with obsessive-compulsive disorder.
abstract: BACKGROUND
  Previous studies have demonstrated that structural deficits and functional connectivity imbalances might underlie the pathophysiology of obsessive-compulsive disorder (OCD). The purpose of the present study was to investigate gray matter deficits and abnormal resting-state networks in patients with OCD and further investigate the association between the anatomic and functional alterations and clinical symptoms.
  
  
  METHODS
  Participants were 33 treatment-naïve OCD patients and 33 matched healthy controls. Voxel-based morphometry was used to investigate the regions with gray matter abnormalities and resting-state functional connectivity analysis was further conducted between each gray matter abnormal region and the remaining voxels in the brain.
  
  
  RESULTS
  Compared with healthy controls, patients with OCD showed significantly increased gray matter volume in the left caudate, left thalamus, and posterior cingulate cortex, as well as decreased gray matter volume in the bilateral medial orbitofrontal cortex, left anterior cingulate cortex, and left inferior frontal gyrus. By using the above morphologic deficits areas as seed regions, functional connectivity analysis found abnormal functional integration in the cortical-striatum-thalamic-cortical (CSTC) circuits and default mode network. Subsequent correlation analyses revealed that morphologic deficits in the left thalamus and increased functional connectivity within the CSTC circuits positively correlated with the total Y-BOCS score.
  
  
  CONCLUSIONS
  This study provides evidence that morphologic and functional alterations are seen in CSTC circuits and default mode network in treatment-naïve OCD patients. The association between symptom severity and the CSTC circuits suggests that anatomic and functional alterations in CSTC circuits are especially important in the pathophysiology of OCD.
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Jingming
authors.initials: J
authors.lastname: Hou
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Lingheng
authors.initials: L
authors.lastname: Song
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Daiquan
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Department of Clinical Psychology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qu
authors.affiliation: Department of Clinical Psychology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Junwei
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Clinical Psychology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Gu
authors.affiliation: Department of Clinical Psychology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Mei
authors.initials: M
authors.lastname: He
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Xie
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D001519:Behavior; D001931:Brain Mapping; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000503:physiopathology*; D003342:Corpus Striatum / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways; D009771:Obsessive-Compulsive Disorder / Q000473:pathology* / Q000503:physiopathology*; D015203:Reproducibility of Results; D013788:Thalamus / Q000503:physiopathology; D055815:Young Adult