Trajectories of depressive symptoms and subjective well-being before and after the onset of the COVID-19 pandemic: Two six-year longitudinal studies

Previous research investigated the trajectories of mental health and well-being during and after the onset of the COVID-19 pandemic. However, less is known about the trajectories of mental health and well-being before, during, and two years after the onset of the pandemic. The aim of the current study was to investigate the trajectory of depression symptoms and subjective well-being (i.e., life satisfaction and positive and negative affect) trajectories over six time points (2017–2022), three before the pandemic and three after the onset of the pandemic. To increase the robustness of our overall conclusions and avoid reliance on data from only one country, we used data from two nationwide representative longitudinal surveys conducted in Germany (GESIS Panel study; N = 5184) and Switzerland (Swiss Household Panel study; N = 17,074). Using covariance pattern mixture models, the results revealed that a four-class model best fit the data. The Stable/resilient trajectory was the most common across outcomes (74.2%–90.1% of participants). Three additional trajectories of Chronic/Low, Upright U-shaped, and Inverted U-shaped emerged in the analysis of negative affect and depression symptoms, while distinct trajectory classes of Worsening, Improving/Stable, and Upright U-shaped also emerged for analyses of positive affect and life satisfaction shaped. In conclusion, there was no evidence of a long-term impact of the pandemic for the vast majority of participants (about 90%). For the remaining participants, the COVID-19 pandemic (along with its exceptional circumstances) was a turning point or a catalyst that reversed, accelerated, or flattened a pre-pandemic trend. These changes in trends were not only negative (e.g., greater depression symptoms), but also positive (e.g., less depression symptoms).