text: 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.
  
  Aims 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.
  
  Method 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.