title: Age at onset and cognitive functioning in schizophrenia.
abstract: BACKGROUND
  Impairments in cognitive functioning are common in schizophrenia, and the degree of impairment may be associated with the individual's age at onset of the disorder.
  
  
  OBJECTIVE
  To examine the effect of age at onset on cognitive functioning using the California Verbal Learning Test, sub-tests from the Wechsler Memory Scale-Revised and sub-scales from the Wechsler Adult Intelligence Scale-Revised among families with schizophrenia.
  
  
  METHODS
  The effect of age at onset on cognitive function in 237 people with schizophrenia from a population-based sample was examined using linear mixed effects models with family as the random effect, and age, gender, chronicity of the illness and number of affected first-degree relatives as fixed effects.
  
  
  RESULTS
  Impairment in verbal learning and memory was associated with earlier disease onset. No association was found for working memory or IQ.
  
  
  CONCLUSIONS
  In patients with early-onset schizophrenia, verbal memory functions in particular should be taken into account in neuropsychological evaluation and efforts at remediation.
authors.affiliation: National Public Health Institute, Department of Mental Health and Alcohol Research, Mannerheimintie 166, 00300 Helsinki, Finland. annamari.tuulio-henriksson@ktl.fi
authors.forename: Annamari
authors.initials: A
authors.lastname: Tuulio-Henriksson
authors.forename: Timo
authors.initials: T
authors.lastname: Partonen
authors.forename: Jaana
authors.initials: J
authors.lastname: Suvisaari
authors.forename: Jari
authors.initials: J
authors.lastname: Haukka
authors.forename: Jouko
authors.initials: J
authors.lastname: Lönnqvist
mesh_terms: D017668:Age of Onset; D002908:Chronic Disease; D003072:Cognition Disorders / Q000523:psychology*; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000453:epidemiology; D012565:Schizophrenic Psychology; D014706:Verbal Learning