Delusions are associated with poor cognitive insight in schizophrenia.

The purpose of the study was to investigate the relationship between the symptoms delusions and hallucinations measured by the Positive and Negative Syndrome Scale and cognitive insight as assessed with the Beck Cognitive Insight Scale (BCIS) in patients with schizophrenia. The BCIS is based on 2 subscales, self-reflectiveness and self-certainty, measuring objectivity, reflectiveness and openness to feedback, and mental flexibility. Overall cognitive insight was defined as the difference between self-reflectiveness and self-certainty. This cross-sectional study of 143 patients showed that the occurrence of delusions is associated with low self-reflectiveness and high self-certainty, reflecting low cognitive insight. Hallucinations in the absence of delusions were associated with high self-reflectiveness and low self-certainty, possibly reflecting more open-mindedness and higher cognitive insight. The present findings suggest that delusions are associated with low cognitive insight, whereas solitary hallucinations may be associated with high cognitive insight.