Psychosocial stress from pre- to post-pandemic times: a latent class growth analysis using data from a German cohort

Purpose The COVID-19 pandemic and containment measures disrupted daily life and worsened mental health. Stress, a key driver of mental disorders, likely intensified during this period. However, longitudinal studies tracking stress trajectories in the general population remain limited. This study aims to identify psychosocial stress trajectories from the pre- to post-pandemic period and examine associated characteristics in a population-based sample from a German city. Methods 966 participants from the German National Cohort study-centre in Halle (240,000 inhabitants in Eastern Germany) were included. Those participated in a six-monthly intensified assessment and completed at least four questionnaires between 2019 and 2024 containing PHQ-Stress module. First, latent class growth analysis identified heterogeneous stress trajectories. Second, associations between class membership and covariates were tested with multinomial logistic regressions. Results We identified four psychosocial stress trajectory classes. Most participants followed an intermediate-level-stress trajectory (58%), while others showed low (30%), high (10%), or peak-recovery (3%) trajectories. Across classes, stress rose over time, with small to moderate changes, mostly early in the pandemic. Membership in the intermediate- or high-stress trajectories was associated with greater pre-pandemic stress, depressive and anxiety symptoms, lower life satisfaction, and greater loneliness at the pandemic’s onset. The peak-recovery class was associated with lower agreeableness and divorce before the pandemic, and reductions in sport activities at its onset. Conclusion Stable patterns of stress predominated, while a small subgroup showed stronger reactivity to pandemic-related strain. These findings suggest that, for most individuals, pre-existing vulnerability and stress levels shape long-term trajectories despite substantial contextual change.