Longitudinal Wisconsin card sorting performance in schizophrenia patients in rehabilitation

Recent investigations into the course of cognitive functioning in schizophrenia have not been able to determine whether cognitive functioning declines, remains stable, or improves over time. This report analyzes Wisconsin Card Sorting Test (WCST) and Wechsler Adult Intelligence Test-Revised Digit Symbol Substitution Test (WAIS-R DSST) performance over time to determine if there is deterioration, improvement, or stability of performance. Data for 46 participants, diagnosed with schizophrenia or schizoaffective disorder that were in a stable phase of illness and actively involved in rehabilitation, were gathered from assessments made at 2 time points on average 4.3 years apart. Results indicated that there was stability in most WCST variables; however, there was significant improvement on WCST perseverative error and on the DSST. Sixty-five percent of the sample improved on 1 or both of the test variables. Furthermore, cognitive test changes were unrelated to type of psychotropic medication and only modestly related to symptom variables. Results indicate that in a stable schizophrenia sample, WCST performance is generally stable over the 3- to 7-year time period, but there are some cognitive variables that may improve even without direct intervention.

schizophrenia, cognition, executive function, rehabilitation, stability