title: P300 aberration in first-episode schizophrenia patients: a meta-analysis.
abstract: BACKGROUND
  Decreased P300 amplitude is one of the most consistent findings in patients with schizophrenia. However, whether prolonged P300 latency occurs in patients with schizophrenia, especially first-episode schizophrenia (FES) patients, remains controversial.
  
  
  METHODS
  A meta-analyses of P300 aberration in FES patients and healthy control(HC) group was conducted. The meta-regression analysis was performed using a random effects model. The pooled standardized effect size (PSES) was calculated as the division of the difference between the means of the two groups by the common standard deviation.
  
  
  RESULTS
  A total of 569 FES patients and 747 HCs were included in this meta-analysis. P300 amplitude was significantly reduced (PSES = -0.83, 95% CI: -1.02-0.65, P = 0.00001) and P300 latency was delayed significantly in FES patients (PSES = -0.48, 95% CI: 0.14-0.81, P = 0.005). The meta-regression analysis showed that task difficulty was a source of heterogeneity.
  
  
  CONCLUSIONS
  The meta-analysis confirms that disrupted information processing is found in FES patients, which is manifested by smaller P300 amplitude and delayed P300 latency.
authors.affiliation: School of Nursing, Second Military Medical University, Shanghai, P.R. China; Department of Statistics, Faculty of Medical Services, Second Military Medical University, Shanghai, P.R. China.
authors.forename: Yao-qin
authors.initials: YQ
authors.lastname: Qiu
authors.affiliation: Department of Medical Psychology, Faculty of psychology and mental healthy, Second Military Medical University, Shanghai, P.R. China.
authors.forename: Yun-xiang
authors.initials: YX
authors.lastname: Tang
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, P.R. China.
authors.forename: Raymond C K
authors.initials: RC
authors.lastname: Chan
authors.affiliation: Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, P.R. China.
authors.forename: Xin-yang
authors.initials: XY
authors.lastname: Sun
authors.affiliation: Department of Statistics, Faculty of Medical Services, Second Military Medical University, Shanghai, P.R. China.
authors.forename: Jia
authors.initials: J
authors.lastname: He
mesh_terms: D016022:Case-Control Studies; D018913:Event-Related Potentials, P300; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012559:Schizophrenia / Q000503:physiopathology*