ObjectivesIt is common, among clinical and non-clinical populations alike, for paranoia and anxiety to co-occur. It has been suggested that anxiety and its related appraisal styles may contribute to development of paranoia. We aimed to evaluate different aspects of risk perception in relation to paranoia and anxiety and to identify specific aspects that may differentiate paranoia from anxiety. This paper consists of two inter-related studies. MethodsStudy 1 compared 30 patients with persecutory delusions, 21 patients with generalized anxiety disorder and 52 healthy controls. Study 2 compared 30 non-clinical individuals with high levels of paranoia and anxiety, 28 individuals with high anxiety only and 36 healthy controls. Within each study, the two symptomatic groups were matched on level of anxiety. Four dimensions of risk perception (i.e. likelihood, harm, controllability, and intentionality) were compared across groups, as measured by the locally validated Risk Perception Questionnaire. ResultsIn both studies, the paranoia and the anxiety groups reported an elevated perceived likelihood of negative events than controls respectively. Only the paranoia groups reported an elevated perceived harm of neutral events than controls. In Study 2, the two at-risk groups attributed more harm and intentionality to negative events than controls. ConclusionAlthough perception of negative events was characteristic in anxiety (with or without paranoia), a biased perception of neutral events as risky was unique to the addition of paranoia. Implications to the transdiagnostic and continual view of psychopathology, and mechanism-based interventions were discussed.