ILLNESS DURATION AND NEUROPSYCHOLOGICAL IMPAIRMENTS IN SCHIZOPHRENIA

This study aims to verify whether cognitive disturbances in schizophre nic patients are associated with illness duration, and to examine the influence of other covariates on neuropsychological disturbances. Sixt y-nine consecutive admissions of schizophrenic patients (DSM-III-R, AP A, 1987) were included to an acute psychiatric unit. Patients were eva luated by a semistructured interview and assessed with the Scale for t he Assessment of Positive Symptoms (SAPS) and the Scale for the Assess ment of Negative Symptoms (SANS). A wide neuropsychological battery, a dapted to Spanish, was used. Variables were transformed to z-scores wh en their distribution was normal, or to log-values in the case of non- normal distributions. Pearson's correlation coefficients with a Bonfer roni correction showed strong relationships between illness duration a nd cognitive performance in neuropsychological tests on visuomotor pro cesses and delayed visual memory. In order to examine the influence of potential covariates on neuropsychological disturbances, stepwise mul tiple regression procedures were performed with each neuropsychologica l measure as a dependent variable, and years of education, age, gender , neuroleptic doses in chlorpromazine equivalents, biperidene doses an d illness duration as independent variables. The longer the illness du ration, the poorer the performance on visuomotor process and delayed v isual memory tasks. Moreover, the neuropsychological disturbances asso ciated with illness duration were different from those related to agin g, educational background, gender and treatment status. These findings suggest the existence of a relationship between cognitive decline in visuomotor and delayed visual memory functions and the length of schiz ophrenic illness. (C) 1998 Elsevier Science B.V. All rights reserved.