FACTOR STRUCTURE OF THE WISCONSIN-CARD-SORTING-TEST - DIMENSIONS OF DEFICIT IN SCHIZOPHRENIA

The aim of this study was to explore the factorial structure of the Wi sconsin Card Sorting Test (WCST) and to identify the dimensions of def icit in schizophrenia. WCST scores in patients with schizophrenia and schizophrenia-related psychosis (n = 292), Ist degree relatives of sch izophrenic patients (n = 91), and normal controls (n = 141) were subje cted to a principal factor analysis followed by orthogonal rotation. T his led to 3 factors, perseveration, failure to maintain set, and idio syncratic sorting. The detected factor structure was found to be invar iant across the schizophrenic and control subsamples. Moreover, it rep licated previous findings from 2 smaller samples. Only perseverations and, to a lesser degree, idiosyncratic sorting appeared to differentia te schizophrenic patients from comparisons. Only perseveration had goo d sensitivity and specificity. as well as the most robust significant correlations with estimates of IQ, attention, and other measures of ex ecutive functioning. Thus, perseveration appears to be the most diagno stically useful and characteristic WCST feature of schizophrenia.