Exploring the relationship between fantasy proneness and delusional beliefs in psychosis and non-clinical individuals

Delusions are a core feature of psychopathology while fantasy proneness (FP) is a trait that describes a pre-disposition towards fantastical thinking, vivid mental imagery and an overactive imagination. The relationship between FP and delusional experiences has not yet been examined in the literature. The current study hypothesised that FP would be significantly associated with and predict delusion severity as well as the associated delusional distress, preoccupation and conviction. Ninety-five patients with current psychosis (schizophrenia and bipolar I disorder) were assessed for overall delusional severity using the PANSS (clinician-rated) and the Peters Delusions Inventory (PDI; self-report). FP was assessed using the Creative Experiences Questionnaire (CEQ). Forty-six healthy control participants also completed the PDI and CEQ. Significant positive correlations were observed between FP and delusion severity in both groups; and distress, preoccupation and conviction in patients only. Linear regression analyses, controlling for manic and depressive symptoms, revealed that greater FP predicted higher levels of severity, distress, preoccupation, and conviction associated with delusions in patients, and higher severity only in healthy controls. The findings highlight the role of specific cognitive biases in delusional experiences, and empirically support models of unusual belief formation and maintenance.