Introduction: A wealth of evidence indicates that neurocognitive deficits are evident in patients with schizophrenia at both illness onset and after many years of treatment. Little is known regarding if or how these deficits change during the lifespan. The goal of the study was to evaluate changes in full-scale intelligence quotient and neurocognitive test performance over a 10-year interval in patients with schizophrenia.
Methods: Twelve patients were administered the Wechsler Adult Intelligence Scale-Revised as a measure of intellectual function and a neuropsychological test battery including measures of attention, verbal and non-verbal memory, language, visuospatial function, problem-solving, and motor function at entry to the study and at a 10-year follow-up.
Results: With the exception of performance on a measure of speeded motor sequencing, there was no significant decline in any of the measures at 10-year follow-up. Results from a measure of sustained auditory attention showed improvement at follow-up.
Discussion: These data support a neurodevelopmental model of schizophrenia for young adult to middle-age patients by suggesting that neurocognitive deficits that emerge either before disease onset or early in the course of the illness remain stable as the patient ages.
Conclusion: Overall, measures of intelligence quotient, as well as specific neurocognitive skills, do not decline over a 10-year period in at least a subgroup of patients with schizophrenia.