A multimethod approach to assessing perseverations in schizophrenia patients

Perseverations have been associated with frontal lobe impairment and are often observed among schizophrenia patients. We assessed perseverations in schizophrenia patients (N = 71) using the Wisconsin Card Sorting Test (WCST) and a new Rorschach perseveration scale which yields three perseveration scores. We also compared the results of the schizophrenia patients with those of a normal comparison group (N = 71). We found that schizophrenia patients demonstrated a high number of perseverations on both the WCST and the Rorschach perseveration scale when compared to the normal comparison subjects. Among schizophrenia patients, WCST perseverative responses were significantly correlated with Rorschach-derived stuck-in-set perseverations, WAIS-R Vocabulary scores and negative symptom ratings. No significant differences in any of the measures of perseveration were found to be associated with diagnostic subtype. Finally, WCST and Rorschach measures for the schizophrenia and normal comparison participants were entered into a logistic regression. The WCST total errors and the three Rorschach perseveration measures resulted in the correct classification of 89.4% of the total cases, with a sensitivity of 91%, specificity of 91% and positive predictive power of 87.8%. These data provide evidence that perseverative behavior is widely observed in schizophrenia patients using a variety of instruments. The authors discuss the benefit of using multiple measures of perseveration in schizophrenia research.