Did perceived stress and intolerance of uncertainty during the COVID-19 pandemic worsen mental health? A longitudinal study of depressive symptoms

BACKGROUND AND OBJECTIVES: The COVID-19 pandemic was marked by global uncertainty, fluctuating safety measures, and major changes to daily living. For those high in intolerance of uncertainty (IU), depressive symptoms emerged or worsened. We examined whether perceived stress mediated the relationship between impacts of the COVID-19 pandemic on symptoms of depression over time, and whether IU moderated these associations. METHODS: 207 adults living in Quebec, Canada, completed an online questionnaire battery at three timepoints, each three months apart, between May 2020 and January 2021. RESULTS: Occupation-related impacts of the pandemic (e.g., changes in income, lay-offs) at time 1 positively predicted perceived stress at time 2, in turn positively predicting depressive symptoms at time 3. Surprisingly, the indirect effect was significant for individuals with low and medium IU, who were sensitive to the actual occupational impacts of the pandemic experienced, but not for those with high IU. Levels of perceived stress were highest overall among individuals with high IU and not significantly predicted by pandemic-related occupational impacts. CONCLUSIONS: Results highlight that there may be a higher susceptibility to perceived stress and depressive symptoms in persons with high intolerance of uncertainty, irrespective of the extent of actual occupational impacts endured during the pandemic.