Unawareness of illness and neuropsychological performance in chronic schizophrenia

This research attempts to explore empirically the relationship between lack of awareness of illness and neuropsychological performance in a group of chronic schizophrenic subjects. Thirty one chronic schizophrenics were administered the recently developed Scale to Assess Unawareness of Mental Disorder (SUMD) and 3 neuropsychological tests that have demonstrated ability to assess frontal lobe performance: the Wisconsin Card Sorting Test (WCST, Verbal Fluency Test and Trials A and B. The number of categories completed and the percent perseverative responses on the WCST were found to significantly correlate with lack of illness awareness as measured by the SUMD. These two WCST variables were also able to significantly discriminate between subjects of high versus low awareness. A discriminant function analysis found that a linear combination of WCST percent perseverative responses and symptom severity could successfully categorize 84% of the aware versus unaware subjects. These results are taken to support the hypothesis that at least in some of its manifestations lack of awareness among chronic schizophrenics has an organic etiology probably mediated by the frontal lobes.