Intolerance of uncertainty as a predictor of anxiety severity and trajectory during the COVID-19 pandemic

Background: Efforts to identify risk and resilience factors for anxiety severity and course during the COVID-19 pandemic have focused primarily on demographic rather than psychological variables. Intolerance of uncertainty (IU), a transdiagnostic risk factor for anxiety, may be a particularly relevant vulnerability factor. Method: N = 641 adults with pre-pandemic anxiety data reported their anxiety, IU, and other pandemic and mental health-related variables at least once and up to four times during the COVID-19 pandemic, with assessments beginning in May 2020 through March 2021. Results: In preregistered analyses using latent growth models, higher IU at the first pandemic timepoint predicted more severe anxiety, but also a sharper decline in anxiety, across timepoints. This finding was robust to the addition of pre-pandemic anxiety and demographic predictors as covariates (in the full sample) as well as pre-pandemic depression severity (in participants for whom pre-pandemic depression data were available). Younger age, lower self/parent education, and self-reported history of COVID-19 illness at the first pandemic timepoint predicted more severe anxiety across timepoints with strong model fit, but did not predict anxiety trajectory. Conclusions: IU prospectively predicted more severe anxiety but a sharper decrease in anxiety over time during the pandemic, including after adjustment for covariates. IU therefore appears to have unique and specific predictive utility with respect to anxiety in the context of the COVID-19 pandemic.