title: Late-onset-psychosis: cognition.
abstract: BACKGROUND
  The objectives of the study were to characterize and compare the cognitive profile and natural evolution of patients presenting late-onset psychotic symptoms (LOPS: onset ≥ 50 years old) to those of elderly patients (≥ 50 years old) with life-long/early-onset schizophrenia (EOS: onset <40 years old).
  
  
  METHODS
  Neuropsychological profiles of 15 LOPS patients were compared to those of 17 elderly EOS patients and to those of two control groups (n = 11/group). The evolution of the two patient groups was compared using an independent diagnostic consensual procedure involving a geriatric psychiatry physician/clinician and a neuropsychologist blinded to the initial psychiatric diagnosis.
  
  
  RESULTS
  EOS presented significant memory and executive impairments when compared to controls but there was no significant difference between LOPS and their controls when age and education were taken into account. However, a detailed inspection of normative data suggests more executive impairments in LOPS than in EOS. The clinical judgment of experts was in favour of significant cognitive deficits with or without dementia in most LOPS (82.3%-94.1%) and EOS (80.0%-93.3%) patients. Regarding evolution, mild cognitive impairment (MCI) and vascular cognitive impairment (VCI) were the most common clinical diagnoses made by geriatric psychiatry physicians/clinicians for the LOPS (40%). In addition, 20% of LOPS versus 5.9% of EOS patients met the diagnostic criteria for dementia by consensus of the experts. Cerebral abnormalities were confirmed (CT scan; SPECT) in 73.3% of LOPS patients.
  
  
  CONCLUSIONS
  The present results suggest cognitive deficits (mostly of executive functions) and vascular and neurodegenerative vulnerability in LOPS. Further studies with larger samples are needed to confirm the present findings.
authors.affiliation: École de psychologie, Université Laval, Québec, Canada. caroline.girard.6@ulaval.ca
authors.forename: Caroline
authors.initials: C
authors.lastname: Girard
authors.forename: Martine
authors.initials: M
authors.lastname: Simard
authors.forename: Robert
authors.initials: R
authors.lastname: Noiseux
authors.forename: Louis
authors.initials: L
authors.lastname: Laplante
authors.forename: Michel
authors.initials: M
authors.lastname: Dugas
authors.forename: François
authors.initials: F
authors.lastname: Rousseau
authors.forename: Nadine
authors.initials: N
authors.lastname: Gagnon
authors.forename: François
authors.initials: F
authors.lastname: Primeau
authors.forename: Evelyn
authors.initials: E
authors.lastname: Keller
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Bernier
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests; D011618:Psychotic Disorders / Q000209:etiology / Q000523:psychology*; D012559:Schizophrenia / Q000209:etiology; D012565:Schizophrenic Psychology