Background and Objectives: The role of interpretation bias in generating and maintaining persecutory beliefs/paranoid ideation is becoming established in the literature, but how negative mood affects this relationship remains unclear. The current study investigated the mediating role of anxiety and depression in the association between interpretation bias and paranoia in patients with persistent paranoia. Methods/Design: We applied the mediation model to clinical data gathered from patients with persistent paranoia (N = 62), and compared how levels of depression and anxiety affected the association between interpretation bias and paranoia. Results: Interpretation bias and anxiety accounted for 43% of the variance in paranoia, while interpretation bias and depression explained 31% of this variance. Levels of anxiety, but not depression, partially mediated the relationship between interpretation bias and paranoid beliefs. Our data suggest that the association between interpretation bias and paranoid beliefs takes effect partly, although not completely, through heightened levels of anxiety. Conclusions: The current study highlighted the role of anxiety as a mediator in the association between interpretation bias and paranoid beliefs in patients with distressing paranoia. These findings inform the potential mechanism underlying cognitive interventions for pathological paranoia. Trial registration: Current Controlled Trials ISRCTN: 90749868. Retrospectively registered on 12 May 2016.
Keywords: Interpretation bias; anxiety; depression; paranoia.