Exploring the Time Trend of Perceived Stress During COVID-19

Background: The COVID-19 pandemic has been associated with elevated stress levels, yet little is known about how perceived stress evolved over time and which factors influenced individual stress trajectories. Aims: This study aimed to examine time trends in perceived stress among German adults during the COVID-19 pandemic and to identify demographic and COVID-19–related moderators of these trajectories. Method: An Ecological Momentary Assessment study was conducted using the mHealth application Corona Health. A total of 288 participants were assessed weekly with the Perceived Stress Scale between December 2020 and February 2022. Linear multilevel models were estimated in R to analyze linear and quadratic time trends in perceived stress and to test moderating effects of age, education, relationship status, and personal experiences with COVID-19 infection. Results: Younger age was associated with higher baseline stress levels. Education and personal experiences with COVID-19 infection significantly moderated stress trajectories over time. Limitations: Some subgroup sample sizes were small. Perceived stress was assessed via self-report, and while the EMA design enhanced ecological validity, it may have reduced internal validity. Conclusion: Although perceived stress declined over time overall, younger individuals experienced higher stress levels during the COVID-19 pandemic, and several demographic and pandemic-related factors influenced stress trajectories. These findings provide real-time insights into stress dynamics, highlight potentially vulnerable populations, and demonstrate the usefulness of mHealth applications for mental health monitoring during public health crises.