title: Opposite effective connectivity in the posterior cingulate and medial prefrontal cortex between first-episode schizophrenic patients with suicide risk and healthy controls.
abstract: OBJECTIVE
  The schizophrenic patients with high suicide risk are characterized by depression, better cognitive function, and prominent positive symptoms. However, the neurobiological basis of suicide attempts in schizophrenia is not clear. The suicide in schizophrenia is implicated in the defects in emotional process and decision-making, which are associated with prefrontal-cingulate circuit. In order to explore the possible neurobiological basis of suicide in schizophrenia, we investigated the correlation of prefrontal-cingulate circuit with suicide risk in schizophrenia via dynamic casual modelling.
  
  
  METHODS
  Participants were 33 first-episode schizophrenic patients comprising of a high suicide risk group (N = 14) and a low suicide risk group (N = 19). A comparison group of healthy controls (N = 15) were matched for age, gender and education. N-back tasking functional magnetic resonance imaging data was collected.
  
  
  RESULTS
  Compared with healthy controls group, the two patients groups showed decreased task-related suppression during 2-back task state versus baseline state in the left posterior cingulate and medial prefrontal cortex; the hyper-connectivity from the left posterior cingulate cortex to the left medial prefrontal cortex existed in both schizophrenic patients groups, but hypo-connectivity in the opposite direction only existed in the schizophrenic patients group with high suicide risk.
  
  
  CONCLUSIONS
  The hyper-connectivity from the left posterior cingulate cortex to the left medial prefrontal cortex may suggest that the abnormal effective connectivity was associated with risk for schizophrenia. The hypo-connectivity in the opposite direction may represent a possible correlate of increased vulnerability to suicide attempt.
authors.affiliation: Mental Health Institute of The Second Xiangya Hospital, Central South University, Changsha, China.
authors.forename: Huiran
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Wei
authors.forename: Haojuan
authors.initials: H
authors.lastname: Tao
authors.forename: Tumbwene E
authors.initials: TE
authors.lastname: Mwansisya
authors.forename: Weidan
authors.initials: W
authors.lastname: Pu
authors.forename: Zhong
authors.initials: Z
authors.lastname: He
authors.forename: Aimin
authors.initials: A
authors.lastname: Hu
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.forename: Zhening
authors.initials: Z
authors.lastname: Liu
authors.forename: Baoci
authors.initials: B
authors.lastname: Shan
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Xue
mesh_terms: D001499:Bayes Theorem; D001931:Brain Mapping; D016022:Case-Control Studies; D003710:Demography; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012307:Risk Factors; D012559:Schizophrenia / Q000503:physiopathology*; D013405:Suicide; D055815:Young Adult