title: Comparison of cognitive deficits among drug-naive patients with schizophrenia and major depressive disorder.
abstract: BACKGROUND
  Cognitive deficits have been well-established among patients with severe mental illness. The aim of this study was to clarify the patterns of cognitive deficits in drug-naive patients with schizophrenia and non-psychotic major depressive disorder (MDD) as compared with controls.
  
  
  METHODS
  Thirty drug-naïve participants with schizophrenia, 30 counterparts with non-psychotic MDD, and 30 age-, sex-, and education years-matched healthy controls were recruited. Neuropsychological tests, including the Wisconsin Card Test (WCST), the Continuous Performance Test (CPT) and the Finger Tapping Test (FTT), were administered.
  
  
  RESULTS
  Patients with schizophrenia performed more poorly than the patients with MDD and the normal controls in the WCST. The patients with schizophrenia and the patients with MDD both performed more poorly than the normal controls in the CPT. The patients with MDD also performed more poorly than the normal controls in the FTT.
  
  
  CONCLUSIONS
  The age of onset of MDD in this study was younger than in previous reports. The cross-sectional design, small sample sizes, and limited numbers of neuropsychological domains in this study are all obstacles to making a clear causal conclusion.
  
  
  CONCLUSIONS
  These results revealed a distinct pattern of neurocognitive dysfunction among drug-naive patients with schizophrenia and MDD, which may imply different underlying neurobiological mechanisms in schizophrenia and MDD.
authors.affiliation: Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Shuo-En
authors.initials: SE
authors.lastname: Hsu
authors.affiliation: Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Department of Psychiatry, National Cheng Kung University Hospital, Dou-Liou Branch, Yunlin, Taiwan; Addiction Research Center, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Kao Chin
authors.initials: KC
authors.lastname: Chen
authors.affiliation: Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Lan-Ting
authors.initials: LT
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Department of Psychiatry, National Cheng Kung University Hospital, Dou-Liou Branch, Yunlin, Taiwan.
authors.forename: Hsin Chun
authors.initials: HC
authors.lastname: Tsai
authors.affiliation: Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Addiction Research Center, National Cheng Kung University, Tainan, Taiwan.
authors.forename: I Hui
authors.initials: IH
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Addiction Research Center, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Po See
authors.initials: PS
authors.lastname: Chen
authors.affiliation: Department of Psychiatry, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Addiction Research Center, National Cheng Kung University, Tainan, Taiwan. Electronic address: ykyang@mail.ncku.edu.tw.
authors.forename: Yen Kuang
authors.initials: YK
authors.lastname: Yang
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003071:Cognition; D003072:Cognition Disorders / Q000523:psychology*; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D018401:Sample Size; D012559:Schizophrenia; D012565:Schizophrenic Psychology
keywords: Cognitive deficit; Drug-naïve; Major depressive disorder; Schizophrenia