Comparison of the Psychosis Proneness Based on the Existence of Persecutory Delusions and Grandiose Delusions in Nonclinical Population

Abstract

ObjectivesZZDelusions are prevalent even among members of the general population, and per- secutory delusions (PDs) and grandiose delusions (GDs) are most frequently found. In this study, we investigated the differences in the dimensions of delusional ideation, reported psychosis proneness, and subjective psychotic symptoms in nonclinical individuals stratified according to the existence of PDs and GDs. MethodsZZA total of 311 nonclinical individuals completed the Peters et al Delusions Inventory 40 (PDI-40), Perceptual Aberration Scale (PAS), Magical Ideation Scale (MIS), Schizotypal Per- sonality Scale (STA), and Symptom Check List-90-R (SCL-90-R). Individuals were grouped ac- cording to four types based on the existence of PDs and GDs in PDI-40 items. ResultsZZAn analysis of variance revealed that the four groups differed significantly in total delu- sion score, distress, preoccupation, and conviction level of delusional ideation, PAS, MAS, STA, in total SCL-90-R scores, and all SCL-90-R sub symptoms. In post-hoc analysis, the group with both PDs and GDs showed the highest scores in all measures, compared with the other three groups. ConclusionZZWe found that individuals with both PDs and GDs have a tendency to possess another delusional ideation and reported more distress, preoccupation, and conviction level of delusional ideation, psychosis proneness, and subjective symptoms. Existence of both PDs and GDs significantly elevated psychosis proneness in comparison to having only either one of them. J Korean Neuropsychiatr Assoc 2013;52:91-97 KEY WORDSZZ Delusion proneness · Persecutory Delusional Ideation · Grandiose Delusional