Reasoning Biases and the Development of Non-clinical Persecutory Ideations: a Systematic Review

Introduction A continuum perspective to understand persecutory delusions suggests that non-clinical persecutory ideations are at the mild end on the same spectrum of persecutory delusions. Based on clinical studies, reasoning biases such as 'jumping to conclusions' (JTC) style, attributional biases (AB), and Theory of Mind (ToM) deficit have been suggested as cognitive risk factors of persecutory delusions, with most robust evidence for JTC. Consistent with the continuum perspective, it is of interest whether these reasoning biases are risk factors of persecutory ideations in the non-clinical population as well. Objectives To examine the association between JTC, AB, ToM deficit, and persecutory ideations in non-clinical populations. Aims To test the following hypotheses: 1. JTC, AB, and ToM deficit will be found in individuals with non-clinical persecutory ideations. 2. Among the three biases, JTC will be more strongly associated with the severity of persecutory ideations in the non-clinical population. Methods Twenty studies from 2001 to 2013 analyzing the relationship between reasoning biases and severity of persecutory ideations in non-clinical populations were systematically reviewed. Results JTC, AB and ToM deficit were found in individuals with non-clinical persecutory thinking but at reduced levels of severity as compared to the clinical populations. A consistent association between JTC and non-clinical persecutory thinking was found across studies. However, studies of AB and ToM deficit yielded conflicting findings. Conclusions Current findings confirm the role of JTC in the pathogenesis of persecutory delusions, and support the development of early interventions targeting data-gathering for individuals at risk of developing persecutory delusions.