title: Comparative study of clinical and neuropsychological characteristics between early-, late and very-late-onset schizophrenia-spectrum disorders.
abstract: OBJECTIVE
  To compare the clinical and neurocognitive profile of early-onset (EOP, <40 years), late-onset (LOP, 40-59 years) and very-late-onset (VLOP, ≥60 years) psychosis.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  Secondary, tertiary, and community mental health care.
  
  
  METHODS
  Patients with a DSM-IV diagnosis of non-affective psychotic disorder were included from two complementary studies (GROUP and PSITE) on genetic and environmental risk factors of psychosis in the Netherlands and Belgium.
  
  
  METHODS
  Main outcome measures were the severity of positive and negative symptoms, quality of life, and age-corrected scores on measures of general intelligence, verbal memory, attention, and executive function. One-year follow-up data were used to validate diagnoses and exclude participants with possible or probable dementia.
  
  
  RESULTS
  286 EOP (85%), 24 LOP (7%) and 28 VLOP (8%) participated. VLOP patients reported significantly more positive symptoms than EOP patients. Age-at-onset groups had similar age-corrected scores on IQ, verbal memory, attention and executive functions. A significantly better performance was found in VLOP compared with LOP on the CAMCOG total score, though scores were still within the normal range. After controlling for possible confounding, however, VLOP differed significantly on an attention accuracy task compared with LOP patients. Re-entering data for probable dementia patients (N = 4) did change the results regarding cognition outcomes.
  
  
  CONCLUSIONS
  VLOP patients show more positive symptoms but do not appear to differ on neuropsychological tests from EOP and LOP when age is controlled for. This questions the idea that VLOP is the expression of underlying neurodegeneration.
authors.affiliation: School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands; Regional Centre for Ambulant Mental Health Maastricht, Maastricht, The Netherlands. Electronic address: m.hanssen@riagg-maastricht.nl.
authors.forename: Manon
authors.initials: M
authors.lastname: Hanssen
authors.affiliation: School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Margriet
authors.initials: M
authors.lastname: van der Werf
authors.affiliation: School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands; Regional Centre for Ambulant Mental Health Maastricht, Maastricht, The Netherlands.
authors.forename: Mike
authors.initials: M
authors.lastname: Verkaaik
authors.affiliation: School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Baer
authors.initials: B
authors.lastname: Arts
authors.affiliation: School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Inez
authors.initials: I
authors.lastname: Myin-Germeys
authors.affiliation: School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Psychosis Studies, Institute of Psychiatry, King's Health Partners, King's College, London, United Kingdom.
authors.forename: Jim
authors.initials: J
authors.lastname: van Os
authors.affiliation: School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Frans
authors.initials: F
authors.lastname: Verhey
authors.affiliation: School of Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Köhler
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001530:Belgium; D003430:Cross-Sectional Studies; D003704:Dementia / Q000175:diagnosis*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009426:Netherlands; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D012016:Reference Values; D012559:Schizophrenia / Q000150:complications* / Q000175:diagnosis*; D055815:Young Adult
keywords: Late-onset schizophrenia-spectrum disorders; clinical phenotype; cognition; late-onset psychosis; neuropsychology