title: Neurocognitive performance and negative symptoms: are they equal in explaining disability in schizophrenia outpatients?
abstract: OBJECTIVE
  The aim of this study is to assess if cognitive variables and symptom dimensions can predict disability in a sample of outpatients with schizophrenia.
  
  
  METHODS
  A cross-sectional sample of 113 individuals with a diagnosis of schizophrenia (DSM-IV criteria) was selected from a computerized register of five Community Mental Health Centers. Patients were assessed by two trained psychologists, with a neuropsychological battery comprising measures for verbal memory, attention, operative memory and abstraction and flexibility functions. Symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS); a socio-demographic and clinical questionnaire, comprising the Disability Assessment Scale (DAS), was also completed. Test scores were standardized (t scores) to performance of healthy controls. To assess the relationship between clinical and sociodemographic factors and disability and cognitive functioning Pearson's correlation coefficients were computed. In order to establish the predictive capacity of the cognitive, clinical and symptom variables on disability linear regression models were fitted.
  
  
  RESULTS
  Mean age of patients was 41.6 years and 68% were male. Higher ratings in the negative dimension were associated with more cognitive deficits. Association with the positive dimension was present but less strong. All disability areas, except for disability in occupational functioning, were partially explained by the negative dimension. Disability in family functioning was also partially explained by attention and number of admissions since onset.
  
  
  CONCLUSIONS
  Negative symptoms are the major source of disability of our sample and are also associated to cognitive functioning. The present findings suggest that further investigation on the mediators between clinical and social outcomes may help to design specific treatments to reduce disability.
authors.affiliation: Research and Development Unit, Sant Joan de Déu- Serveis de Salut Mental, Fundació Sant Joan de Déu, C/ Dr. Antoni Pujadas 42, 08830, St. Boi de Llobregat, Barcelona, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Villalta-Gil
authors.forename: Míriam
authors.initials: M
authors.lastname: Vilaplana
authors.forename: Susana
authors.initials: S
authors.lastname: Ochoa
authors.forename: Josep Maria
authors.initials: JM
authors.lastname: Haro
authors.forename: Montserrat
authors.initials: M
authors.lastname: Dolz
authors.forename: Judit
authors.initials: J
authors.lastname: Usall
authors.forename: Jorge
authors.initials: J
authors.lastname: Cervilla
mesh_terms: D000328:Adult; D000339:Affect; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care; D001921:Brain / Q000503:physiopathology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy; D012720:Severity of Illness Index