The Utility of the Wisconsin Card Sorting Test in Differential Diagnosis of Cognitive Disorders in Iranian Psychiatric Patients and Healthy Subjects

OBJECTIVE: The Wisconsin Test Card Sorting Test (WCST) is a neuropsychological test that has been suggested as a more specific test for frontal lobes dysfunctions. This study was designed to determine whether WCST is able to differentiate between Iranian psychiatric patients with cognitive disorders and normal subjects, and whether WCST scores are related to severity of symptoms in depressive and schizophrenic patients. METHOD: Participants were four groups: schizophrenics with positive symptoms (n=25); schizophrenics with negative symptoms (n=25); major depressives (n=25); and normal subjects (n=25). All subjects were tested individually using WCST. To analyze the data, various descriptive statistics, ANOVA, t-test and multiple regression analysis were used. RESULTS: Regarding the number of categories (P<0.001) and the rate of perseverative errors (P<0.01), according to the results, the normal subjects performed significantly better than patient groups on WCST, although the differences between patient groups were not significant. Our results also showed that greater positive or depressive symptoms were not associated with poorer scores on WCST performance. Only the level of severity of negative symptoms predicted scores on perseverative errors. CONCLUSION: It is concluded that WCST can differentiate Iranian psychiatric patients with cognitive disorders from normal subjects, but it is not able to clearly differentiate schizophrenic patients with negative symptoms from those with positive symptoms and depressives. Only severity of negative symptoms affects WCST performance