The contribution of optimism and hallucinations to grandiose delusions in individuals with schizophrenia

Grandiose delusions (GDs) are defined as false beliefs about having an inflated worth, power, or a special identity which are firmly sustained despite undeniable evidence to the contrary. Although it is the second most commonly encountered delusional beliefs, GDs have received little attention. Thus, in this study, we explored the role of future expectations and sensitivity to reward in GDs in schizophrenia (SZ) disorder. In total, 115 SZ patients completed measures of positive and negative symptoms, sensitivity to reward, depression, and a task in which individuals were asked to estimate the probability that positive, negative and neutral events will occur in the future. Correlation and Linear Regression analyses were performed in order to determine whether sensitivity to reward and future expectations are associated with GDs. Regressions showed that hallucinations and future positive expectations were significantly associated with GDs. In conclusion, the present study showed that higher optimism regarding the future might be important psychological processes associated with the maintenance of GDs in SZ patients. Moreover, it is possible that patients experiencing hallucinations may interpret this phenomenon as a kind of special ability or power, resulting in turn in GDs maintenance. Implications of these findings and directions for future research are discussed. (C) 2019 Elsevier B.V. All rights reserved.