Acknowledgements: We would like to thank Ken Benoit, Theresa Gessler, Frank Neffke, Max Pellert, Taha Yasseri and the other participants of the Complexity Science Hub Workshop on the Great Resignation for their feedback and discussions. We are also thankful to Mikołaj Biesaga for providing the code in Python to collect Reddit data and to Sebastian von Beck and Fariba Dorpoush for their work as Research Assistants. Finally, we would like to thank Joshua Becker, Marco Pangallo, and Ingo Weller for their feedback on the manuscript.Funder: JSMF FellowhipTo study the causes of the 2021 Great Resignation, we use text analysis and investigate the changes in work- and quit-related posts between 2018 and 2021 on Reddit. We find that the Reddit discourse evolution resembles the dynamics of the U.S. quit and layoff rates. Furthermore, when the COVID-19 pandemic started, conversations related to working from home, switching jobs, work-related distress, and mental health increased, while discussions on commuting or moving for a job decreased. We distinguish between general work-related and specific quit-related discourse changes using a difference-in-differences method. Our main finding is that mental health and work-related distress topics disproportionally increased among quit-related posts since the onset of the pandemic, likely contributing to the quits of the Great Resignation. Along with better labor market conditions, some relief came beginning-to-mid-2021 when these concerns decreased. Our study underscores the importance of having access to data from online forums, such as Reddit, to study emerging economic phenomena in real time, providing a valuable supplement to traditional labor market surveys and administrative data