Frank Larøi

Associations between delusion proneness and personality structure in non-clinical participants: Comparison between young and elderly samples

Background: Few studies have explored the prevalence of delusions in the non-clinical, elderly population. In addition, the association between personality structure and delusions remains poorly investigated. The aims of the present study were, first, to explore the relation between age and the prevalence of delusion proneness and, second, to examine the association between personality and delusion proneness in young and elderly participants. Sampling and Methods: A sample of young (n = 343; aged 18–30 years) and elderly (n = 183; aged 60–75 years) non-clinical participants completed the 21-item version of the Peters et al. Delusions Inventory (PDI-21), an elaborated and validated version of the Launay-Slade Hallucinations Scale, and the revised version of the NEO Personality Inventory (NEO-PI-R). Results: Mean scores on the PDI-21 for the young and elderly participants were compared. An independent t test revealed that the total mean scores were significantly higher for young participants compared to elderly participants. PDI-21 items were then re-grouped into previously validated factors. Independent t tests revealed that young participants had significantly higher scores for items related to suspiciousness and persecutory ideas, thought disturbances and jealousy, grandiose ideas, paranormal beliefs and apocalyptic ideas. In contrast, elderly participants scored significantly higher than young participants on the religious ideation factor. Associations between scores on the NEO-PI-R and the PDI-21 were then examined for the two groups. For the young sample, correlational analyses revealed a significant relationship between the total score on the PDI-21 and scores on the openness, neuroticism and agreeability facets of the NEO-PI-R. For the elderly sample, correlational analyses revealed a significant relationship between the total score on the PDI-21 and the openness facet of the NEO-PI-R. Discussion: Results from the study reveal that delusional ideation is a relatively common experience for both young and elderly non-clinical participants. In addition, findings are in line with studies suggesting that neuroticism and aspects related to neuroticism increase the risk for the development of psychotic symptoms such as delusions. However, it is important to mention that, because the present study includes non-clinical subjects and is a cross-sectional study, more research is needed.