title: Negative symptoms and executive function in schizophrenia: does their relationship change with illness duration?
abstract: BACKGROUND
  Negative symptoms and cognitive dysfunction are of crucial functional and prognostic importance in schizophrenia. However, the nature of the relationship between them and the factors that may influence it have not been well established.
  
  
  OBJECTIVE
  To investigate whether the relationship between negative symptoms and executive function changes according to the duration of illness in schizophrenia.
  
  
  METHODS
  The Positive and Negative Syndrome Scale was used to assess psychopathology and the Wisconsin Card Sorting Test (WCST) to evaluate executive function in a sample of 200 schizophrenic patients who were classified in 3 groups according to their duration of illness: up to 5 years (short duration group), 6-20 years (intermediate duration group) and over 20 years of illness (long duration group).
  
  
  RESULTS
  Medium-sized correlations were found between negative symptoms and WCST performance as assessed by the number of completed categories in all 3 groups. However, differences were found according to the duration of schizophrenia. For patients in the short duration group, negative symptoms correlated with WCST nonperseverative errors, but for those in the long duration group the correlation was with perseverative errors.
  
  
  CONCLUSIONS
  We found a differential relationship between negative and cognitive symptoms in different stages of schizophrenia. Illness duration should be considered when studying the relationship between negative symptoms and cognition.
authors.affiliation: Department of Psychiatry, Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain. alexbagney@gmail.com
authors.forename: Alexandra
authors.initials: A
authors.lastname: Bagney
authors.forename: Roberto
authors.initials: R
authors.lastname: Rodriguez-Jimenez
authors.forename: Isabel
authors.initials: I
authors.lastname: Martinez-Gras
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Sanchez-Morla
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Santos
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Jimenez-Arriero
authors.forename: Antonio
authors.initials: A
authors.lastname: Lobo
authors.forename: Patrick D
authors.initials: PD
authors.lastname: McGorry
authors.forename: Tomas
authors.initials: T
authors.lastname: Palomo
mesh_terms: D000328:Adult; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000523:psychology*; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology; D012565:Schizophrenic Psychology; D013997:Time Factors