POOR DIFFERENTIAL PERFORMANCE ON THE WISCONSIN CARD SORTING TEST IN SCHIZOPHRENIA, MOOD DISORDER, AND TRAUMATIC BRAIN INJURY

The utility of the Wisconsin Card Sorting Test (WCST) to effectively d ifferentiate diagnostic groups was evaluated. Performance on the WCST was contrasted among samples of schizophrenic, mood-disordered, and tr aumatically brain-injured patients, as well as normal controls. The co ntrols performed significantly better than all three patient groups, w ithout any differentiation among the patient samples. The pattern of p erformance, over time, also did not differ between the groups. The poo r discrimination between the patient groups may provide evidence for m ultiple cognitive processes being involved in WCST performance (e.g., attention, executive functioning). Consequently, similar WCST performa nce could result from deficiencies in different cognitive processes.