1.5 years pandemic - Psychological burden over the course of the COVID-19 pandemic in Germany: A nine-wave longitudinal community study

Background: The dynamic COVID-19 pandemic has been associated with mental strain. However, most studies focused primarily on the beginning of the pandemic and rarely took into account the long-term course. The aim of this prospective-longitudinal study was to investigate levels and changes of pandemic-related fears, unspecific anxiety, depressive symptoms, and psychosocial-behavioral factors over the first 1.5 years of the pandemic.Methods: We conducted a nine-wave longitudinal online-survey from March 2020 to October 2021 with a total of 8148 participants of the adult general population in Germany. Descriptive examination and multilevel analysis were carried out to assess psychological burden, risk-bearing and protective psychosocial-behavioral factors, and associations with sociodemographics and the pandemic's duration and severity over the course of the pandemic.Results: Symptoms of mental strain fluctuated across the pandemic and displayed a relative maximum at the pandemic's early beginning and during the second and third COVID-19 waves. Most participants (approximately 67.4 %-82.1 %) reported mild and transient symptoms, but a substantial portion (approximately 17.9 %-32.6 %) experienced pronounced mental health problems during the pandemic. Symptom severity was negatively asso-ciated with the duration of the pandemic and positively associated with the rate of new infections.Limitations: The observational study design, non-probability-sampling methods, and online self-report assess-ments limit the generalizability of our results.Conclusions: The fluctuating course of psychological burden during the pandemic emphasizes the relevance of continuous monitoring during this challenging time. Particularly individuals with pronounced subclinical symptoms or manifesting mental disorders should be targeted with adequate prevention and early intervention programs.