title: Persistence of psychotic symptoms as an indicator of cognitive impairment in methamphetamine users.
abstract: BACKGROUND
  Prolonged exposure to methamphetamine (meth) has neurotoxic effects and impairs neurocognitive functions. This study aims to ascertain whether meth users who experience persistent psychosis suffer more severe cognitive impairment than those not experiencing persistent psychosis.
  
  
  METHODS
  This cross-sectional study includes 252 participants: 25 meth users without psychosis (METH-P), 50 with brief psychosis (METH+BP), and 56 with persistent psychosis (METH+PP), as well as 54 patients with schizophrenia and 67 healthy controls. The neurocognitive function and clinical psychopathology of each patient were evaluated with the Brief Assessment of Cognition in Schizophrenia (BACS) and the Brief Psychiatric Rating Scale (BPRS), respectively.
  
  
  RESULTS
  All cognitive domains evaluated with BACS (verbal memory, working memory, motor speed, verbal fluency, attention and processing speed, executive function, and composite scores) in METH+PP patients were similar to those in the schizophrenia patients and were worse than those in METH-P, METH+BP, and the healthy control subjects. Furthermore, cognitive functioning in meth users that did not experience persistent psychosis showed no statistically significant difference compared with the healthy control subjects. Among the meth users in this study, the negative symptom scores in the BPRS correlated to cognitive performance on the BACS, with the exception of motor speed.
  
  
  CONCLUSIONS
  Meth users display heterogeneity in their psychotic symptoms and cognitive profiles. Therefore, persistent psychotic symptoms may denote a risk for cognitive decline among meth users. Further longitudinal studies should be performed in the future to clarify the causal relationship between cognitive deficits and the development of persistent psychosis.
authors.affiliation: Department of Psychiatry, Chang Gung Memorial Hospital, Keelung, Taiwan; Chang Gung University School of Medicine, Taoyuan, Taiwan.
authors.forename: Chih-Ken
authors.initials: CK
authors.lastname: Chen
authors.affiliation: Taipei City Hospital and Psychiatric Center, Taipei, Taiwan.
authors.forename: Shih-Ku
authors.initials: SK
authors.lastname: Lin
authors.affiliation: Department of Psychiatry, Chang Gung Memorial Hospital, Keelung, Taiwan; Chang Gung University School of Medicine, Taoyuan, Taiwan.
authors.forename: Yi-Chih
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Taipei City Hospital and Psychiatric Center, Taipei, Taiwan; Taipei Medical University, Taipei, Taiwan.
authors.forename: Ming-Chy
authors.initials: MC
authors.lastname: Huang
authors.affiliation: Department of Psychiatry, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan.
authors.forename: Tzu-Ting
authors.initials: TT
authors.lastname: Chen
authors.affiliation: Department of Psychiatry, Chang Gung Memorial Hospital, Keelung, Taiwan; Chang Gung University School of Medicine, Taoyuan, Taiwan.
authors.forename: Shao Chun
authors.initials: SC
authors.lastname: Ree
authors.affiliation: Department of Child and Adolescent Psychiatry, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan. Electronic address: wangliangjen@gmail.com.
authors.forename: Liang-Jen
authors.initials: LJ
authors.lastname: Wang
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008694:Methamphetamine; D008875:Middle Aged; D009483:Neuropsychological Tests; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology
chemical_list: D008694:Methamphetamine
keywords: Cognition; Neuropsychological test; Psychosis; Psychostimulant; Schizophrenia