title: Altered BDNF is correlated to cognition impairment in schizophrenia patients with tardive dyskinesia.
abstract: BACKGROUND
  Long-term antipsychotic treatment for schizophrenia is often associated with the emergence of tardive dyskinesia (TD), which is linked to greater cognitive impairment. Brain-derived neurotrophic factor (BDNF) plays a critical role in cognitive function, and schizophrenia patients with TD have lower BDNF levels than those without TD.
  
  
  OBJECTIVE
  This study examines the BDNF levels, the cognitive function, and the association of BDNF with cognitive function in schizophrenia patients with or without TD.
  
  
  METHODS
  We recruited 83 male chronic patients with (n=35) and without TD (n=48) meeting DSM-IV criteria for schizophrenia and 52 male control subjects. We examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and BDNF levels for all subjects. Positive and Negative Symptom Scale (PANSS) and the Abnormal Involuntary Movement Scale (AIMS) were assessed in patients.
  
  
  RESULTS
  BDNF levels were lower in patients with than those without TD (p<0.05). RBANS total score (p<0.01) and subscales of immediate memory, visuospatial/constructional performance, and attention were lower in patients with than those without TD (all p<0.05). BDNF levels were positively associated with immediate memory in patients without TD, but negatively in TD patients (both p<0.05). Multiple regression analysis confirmed that in either TD or non-TD group, BDNF was an independent contributor to immediate memory (both p<0.05).
  
  
  CONCLUSIONS
  BDNF may be involved in the pathophysiology of TD. While the associations between BDNF and cognition in both TD and non-TD patients suggest a close relationship between BDNF and cognition, the different directions may implicate distinct mechanisms between TD and non-TD patients.
authors.affiliation: School of Biomedical Sciences and Pharmacy, Faculty of Health, The University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia.
authors.forename: Jing Qin
authors.initials: JQ
authors.lastname: Wu
authors.forename: Da Chun
authors.initials: DC
authors.lastname: Chen
authors.forename: Yun Long
authors.initials: YL
authors.lastname: Tan
authors.forename: Shu Ping
authors.initials: SP
authors.lastname: Tan
authors.forename: Li
authors.initials: L
authors.lastname: Hui
authors.forename: Men Han
authors.initials: MH
authors.lastname: Lv
authors.forename: Jair C
authors.initials: JC
authors.lastname: Soares
authors.forename: Xiang Yang
authors.initials: XY
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003072:Cognition Disorders / Q000097:blood* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000097:blood* / Q000453:epidemiology; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology
chemical_list: D014150:Antipsychotic Agents; D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human