Delusional Ideations across Cultures: India, Turkey, South Korea, & USA

In contemporary classifications of mental disorders, such as DSM-5 and ICD-10, delusions are considered as keystone symptoms for the diagnosis of psychotic disorders. Using Peters et al.’s (2004) delusions inventory, PDI-21, we report distribution of delusional beliefs among a group of undergraduate students in India (n=207), Turkey (n=47), South Korea (n=148) and USA (n= 75). The data were collected between June, 2014 - December, 2017 from the four countries. The PDI-21 measures delusional beliefs in normal population along the dimensions of conviction, preoccupation and distress. Each item is endorsed by the person indicating whether he/she had a delusional experience in a particular area. If the answer is, “Yes,” then, he/she is asked to rate its severity on a 5-point scale along the dimensions of conviction, and preoccupation. The results are being discussed in terms of differences in the endorsement rate of the delusional ideations. There are significant differences in the endorsement of delusional ideations across cultures. The level of conviction, distress, and preoccupation also differ across the cultures. In addition to distribution of delusions along the Peters et al.’s (1999b) dimensions of conviction, distress, and preoccupation, we also found evidence of reduced delusional beliefs with age. The younger sample report higher prevalence of delusions than the older age-group in the U.K. sample as reported by Peters et al. Scores did not show bimodal distributions, and PDI-21 scores empirically supported Kellog’s (1908) observations of delusional beliefs being distributed on a continuum among the normal population across different cultures.