Background: The COVID-19 pandemic caused multiple stressors that may lead to symptoms of adjustment disorder.Objective: We longitudinally examined relationships between risk and protective factors, pandemic-related stressors and symptoms of adjustment disorder during the COVID-19 pandemic, as well as whether these relationships differed by the time of assessment.Method: The European Society for Traumatic Stress Studies (ESTSS) ADJUST Study included N = 15,169 participants aged 18 years and above. Participants from 11 European countries were recruited and screened three times at 6-month intervals from June 2020 to January 2022. Associations between risk and protective factors (e.g. gender), stressors (e.g. fear of infection), and symptoms of adjustment disorder (AjD, ADNM-8) and their interaction with time of assessment were examined using mixed linear regression.Results: The following predictors were significantly associated with higher AjD symptom levels: female or diverse gender; older age; pandemic-related news consumption >30 min a day; a current or previous mental health disorder; trauma exposure before or during the pandemic; a good, satisfactory or poor health status (vs. very good); burden related to governmental crisis management and communication; fear of infection; restricted social contact; work-related problems; restricted activity; and difficult housing conditions. The following predictors were associated with lower AjD levels: self-employment or retirement; working in healthcare; and face-to-face contact ≥ once a week with loved ones or friends. The effects of the following predictors on AjD symptoms differed by the time of assessment in the course of the pandemic: a current or previous mental disorder; burden related to governmental crisis management; income reduction; and a current trauma exposure.Conclusions: We identified risk factors and stressors predicting AjD symptom levels at different stages of the pandemic. For some predictors, the effects on mental health may change at different stages of a pandemic.
