***Replication files for "COVID-19 mitigation policies and psychological distress in young adults" by Michelle Jackson and Joanna Lee Williams*** **Abstract** The COVID-19 pandemic has seen an unusually high proportion of the population suffering from mental health difficulties, but of particular concern is the disproportionate increase in psychological distress among younger adults. In this article, we exploit an explanatory sequential mixed-methods design to examine which aspects of the COVID-19 pandemic 18-25-year-olds found most challenging. We report analyses of American Voices Project (AVP) qualitative in-depth interview data, a MyVoice text-message open-ended survey, and Census Bureau Household Pulse Survey (HPS) data, all collected in 2020. Our interview and text-message results show that young adults were distressed about the effects of COVID-19 on the health of loved ones and older Americans. Young adults expressed concerns that the pandemic was not being treated sufficiently seriously by some politicians and the general public. The policy response was seen to be inadequate to the task of containing the disease, and some feared that the pandemic would never end. Statistical analyses of the HPS confirm that young adults’ scores on the HPS’s anxiety scale were significantly negatively associated with state-level policy responses. Overall, our results show that young adults found virus mitigation strategies challenging, but that a strong policy response was associated with reduced levels of psychological distress. Our results suggest that public health policy might have also operated as mental health policy during the COVID-19 pandemic. Available at: https://doi.org/10.1016/j.ssmmh.2021.100027