Intolerance of uncertainty predicts paranoia over time: Evidence from a UK sample

Paranoia, often associated with schizophrenia spectrum disorders, also exists on a continuum with ordinary mistrust and is prevalent in non-clinical populations. Recent research suggests that Intolerance of Uncertainty (IU), a dispositional trait reflecting a negative response to uncertainty, may play a significant role in predicting paranoia. This study aimed to examine the longitudinal relationship between IU and paranoia, using data from the Covid-19 Psychological Research Consortium Study (C19PRC). 2025 participants representative of the UK population were recruited and assessed across three waves over nine months. Path analysis revealed that IU consistently predicted paranoia over time, even after controlling for negative affective traits such as neuroticism, and common co-occurring symptoms such as anxiety, and depression. Partial correlation analyses revealed stronger relationships between paranoia and Inhibitory IU than Prospective IU. These findings suggest that IU is a stable and independent predictor of paranoia. This study extends previous cross-sectional research by providing longitudinal evidence of associations between IU and paranoia and suggests that IU may represent a promising target for future research on intervention strategies.