Janine Stein ^1,2* Alexander Pabst ² Klaus Berger ³ André Karch ³ Henning Teismann ³ Fabian Streit ⁴ Hans J. Grabe ⁵ Rafael T. Mikolajczyk ⁶ Janka Massag ⁶ Wolfgang Lieb ⁷ Stefanie Castell ⁸ Jana-Kristin Heise ⁸ Matthias Schulze ⁹ Sylvia Gastell ⁹ Volker Harth ¹⁰ Nadia Obi ¹⁰ Annette Peters ¹¹ Marie-Theres Huemer ¹¹ Patricia Bohmann ¹² Michael Leitzmann ¹² Sabine Schipf ¹³ Claudia Meinke-Franze ¹³ Antje Hebestreit ¹⁴ Daniela C. Fuhr ¹⁴ Karin B. Michels ¹⁵ Stefanie Jaskulski ¹⁵ Hannah Stocker ¹⁶ Lena Koch-Gallenkamp ¹⁷ Stefan N. Willich ¹⁸ Thomas Keil ¹⁸ Markus Löffler ¹ Kerstin Wirkner ¹ Steffi G. Riedel-Heller ¹

• ¹ Leipzig University, Leipzig, Germany
• ² Institute for Social Medicine, Occupational Medicine and Public Health, University Hospital Leipzig, Leipzig, Lower Saxony, Germany
• ³ University of Münster, Münster, North Rhine-Westphalia, Germany
• ⁴ Heidelberg University, Heidelberg, Baden-Württemberg, Germany
• ⁵ University of Greifswald, Greifswald, Mecklenburg-Vorpommern, Germany
• ⁶ University of Halle, Medical Faculty, Halle, Germany
• ⁷ University of Kiel, Kiel, Schleswig-Holstein, Germany
• ⁸ Helmholtz Center for Infection Research, Department of Epidemiology, Braunschweig, Germany
• ⁹ University of Potsdam, Potsdam, Brandenburg, Germany
• ¹⁰ University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany
• ¹¹ Helmholtz Center München, Helmholtz Association of German Research Centres (HZ), Neuherberg, Bavaria, Germany
• ¹² University of Regensburg, Regensburg, Bavaria, Germany
• ¹³ Universitätsmedizin Greifswald, Greifswald, Mecklenburg-Vorpommern, Germany
• ¹⁴ Leibniz Institute for Prevention Research and Epidemiology - BIPS, Bremen, Bremen, Germany
• ¹⁵ University of Freiburg, Freiburg, Baden-Wurttemberg, Germany
• ¹⁶ German Cancer Research Center (DKFZ), Heidelberg, Baden-Württemberg, Germany
• ¹⁷ German Cancer Consortium, German Cancer Research Center (DKFZ), Heidelberg, Baden-Württemberg, Germany
• ¹⁸ Charité University Medicine Berlin, Berlin, Baden-Wurttemberg, Germany

Background: The COVID-19 pandemic prompted a range of studies on mental health, with mixed results. While numerous studies reported worsened conditions in individuals with pre-existing mental disorders, others showed resilience and stability in mental health. However, longitudinal data focusing on the German population are sparse, especially regarding effects of age and pre-existing mental disorders during the early stages of the pandemic. Objectives: To assess the interplay between psychiatric history, age, and the timing of the pandemic, with a focus on understanding how these factors relate to the severity of depression and anxiety symptoms. Methods: Exploratory analyses were based on 135,445 individuals aged 20 to 72 years from the German National Cohort (NAKO). Depressive and anxiety symptoms were assessed before and after the first wave of the pandemic. Inferential statistical analyses and negative binomial regression models were calculated. Results: Persons with a self-reported psychiatric history exhibited comparable levels of depression and anxiety symptom severity after the first wave of the pandemic compared to the time before. In contrast, individuals without a psychiatric history, particularly those in their 20s to 40s, experienced an increase in mental health symptom severity during the first wave of the pandemic. Limitations: Analyses focuses on the first wave of the pandemic, leaving the long-term mental health effects unexplored. Conclusions: Future research should consider age-specific and mental-health-related factors when addressing global health crises. Additionally, it is important to explore factors influencing resilience and adaptation, aiming to develop targeted interventions and informed policies for effective mental health management during pandemics.