77. Neurocognitive findings in schizophrenic subjects with above average IQ

Abstract

Schizophrenia has been characterized as a disorder producing generalized deficits across multiple cognitive domains. We hypothesized that schizophrenic subjects with high IQ, while impaired in some domains, would show areas of preserved function. Using each WAIS-R subset and the full-scale test as sort criteria (VIQ, PIQ or FSIQ > 110) comparisons were performed between high-IQ (n = 10–18 depending on criterion) and average-IQ patients (n = 72–80), and high-IQ (n = 10–11), and average-IQ (n = 15–16) controls. Mean IQs for the groups created by these criteria were 118–120 (high) and 91–95 (low) for patients, and 120–123 and 97–101 for controls. Matching for IQ, comparison of patients to controls revealed different patterns of impairments in the high-IQ and average-IQ groups. Average-IQ patients were impaired on all tasks except Rey Copy and Recall (all criteria) and Stroop Color Naming (except PIQ). For high-IQ patients, Finger-Tapping (Dominant and Non-Dominant) and Stroop Color Naming were preserved regardless of sort criteria. However, in comparing the high-IQ groups, additional preserved functions were identified when the more specific scales were used. High- and average-IQ schizophrenic subjects performed differently from each other on Speed of Comprehension and Trails B regardless of sort method, on Rey Copy and Recall (sorted by PIQ), and on Stroop Color Naming (sorted by VIQ). These findings indicate that individuals with schizophrenia do not demonstrate generalized impairments in all cognitive domains, and that additional areas of preserved function are observed in “higher-functioning patients.”