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. Aims: To examine the effect of age at onset on cognitive functioning using the California Verbal LearningTest, 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.