title: Contingent negative variation in patients with deficit schizophrenia or bipolar I disorder with psychotic features: measurement and correlation with clinical characteristics.
abstract: BACKGROUND
  Schizophrenia is a highly heterogeneous disease. Event-related potentials have been regarded to establish intermediate phenotypes of schizophrenia. Our previous study found that patients with deficit schizophrenia (DS) are relatively homogeneous and show a significantly longer onset latency of contingent negative variation (CNV) expectancy wave.
  
  
  OBJECTIVE
  To further examine CNV in patients with first-episode and drug-naïve DS or bipolar I disorder (BP I) with psychotic features, and also investigate correlations between CNV and clinical characteristics in DS and BP I.
  
  
  METHODS
  We elicited a CNV using an alarm (S1)-imperative (S2) paradigm in 30 DS patients or 33 BP I with psychotic features as well as 40 healthy controls.
  
  
  RESULTS
  CNV amplitude was significantly smaller and reaction time significantly longer in the DS and BP I groups than in healthy controls. Post-imperative negative variation (PINV) interval was significantly shorter in the DS group than in healthy controls. The onset latency of CNV expectancy wave was significantly longer and PINV area significantly smaller in the DS group than in the other groups. In the DS group, CNV amplitude and PINV interval correlated negatively with the subscale of negative symptoms on the Positive and Negative Syndrome Scale (PANSS); CNV amplitude also correlated negatively with disease duration. In the BP I group, CNV amplitude and reaction time showed no correlation with clinical features.
  
  
  CONCLUSIONS
  CNV amplitude is a common trait marker for psychosis. The onset latency of CNV expectancy wave appears to be a specific trait marker and may be used to identify candidate genes for DS.
authors.affiliation: Zhe Li, M.D., The Mental Health Center and the Psychiatric Laboratory, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University , Chengdu, Sichuan 610041 , China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Deng
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zheng
authors.forename: Mingli
authors.initials: M
authors.lastname: Li
authors.forename: Yinfei
authors.initials: Y
authors.lastname: Li
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Han
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Ma
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Xiehe
authors.initials: X
authors.lastname: Liu
authors.forename: Tao
authors.initials: T
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D003265:Contingent Negative Variation; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time; D012559:Schizophrenia / Q000503:physiopathology*; D055815:Young Adult
keywords: Bipolar disorder; Contingent negative variation; Deficit schizophrenia; Event-related potentials