Memory and intellectual deficits do not decline with age in schizophrenia

Cognitive deficits in schizophrenia are reported to be more consistent with a static encephalopathy than a dementing disorder. This study investigates memory and intellectual decline in 62 chronic schizophrenic subjects using the Wechsler Adult Intelligence Scale-Revised (WAIS-R), the Rivermead Behavioural Memory Test and the National Adult Reading Test (NART) in a cross-sectional study using five age cohorts (18-29, 30-39, 40-49, 50-59 and 60-69 years of age) and then by two cohorts (young: 18-39; older: 40-69). A second method of investigating intellectual decline was implemented by estimating the discrepancy score between WAIS-R (current IQ) and NART (premorbid IQ) for each subject. No significant differences were found in WAIS-R Full Scale. Verbal and Performance IQ and memory functioning across the five age cohorts (and when using two age groups). A significant difference in test scores was found using the Picture Completion and Digit Symbol subtests of the WAIS-R. The differences were not related to age or duration of illness. No significant difference in scores were evident in the remaining WAIS-R subtests. These results support previous findings that schizophrenia is more consistent with a static encephalopathy than a dementing disorder and that intellectual and memory function does not markedly decline with age.