No deficit in Wisconsin Card Sorting Test performance of schizophrenic patients' first-degree relatives

The Wisconsin Card Sorting Test (WCST) was administered to 92 schizophrenic patients, 25 first-degree relatives and 60 normal subjects in order to investigate whether this task could be considered a trait marker of vulnerability to schizophrenia. The schizophrenic patients performed significantly worse than either their relatives or normal subjects, but unaffected relatives did not differ from controls. Our results suggest that WCST performance is more likely a feature inherent to the disease process rather than an index of the genetic susceptibility to the illness.