Common sense, insight, and neuropsychological test performance in schizophrenia patients.

We report an exploratory study examining the interrelationships among common sense, insight into psychosis, and performance on a battery of neuropsychological tests in 32 patients with schizophrenia evaluated at the time of discharge from involuntary hospitalization at a State psychiatric hospital. Common sense, as measured by the Social Knowledge Questionnaire, was associated with better performance across tests measuring parietal lobe functioning and vocabulary. In addition, patients with more common sense were more likely to say that they were ill and needed treatment. A global measure of insight, the Insight and Treatment Attitudes Questionnaire (ITAQ), was related to performance on a test of left parietal lobe function. However, the responses to the ITAQ item that may best reflect current awareness of mental illness in patients at the time of discharge ("After you are discharged, is it possible you may have mental problems again?") were related to performance on tests of the functioning of the prefrontal lobes and the right and left parietal lobes. These results add to the growing evidence that some of the deficits in awareness of illness among patients with schizophrenia are related to the neuropsychological dysfunction commonly seen in patients with this disorder.