摘要:The Coronavirus Disease (COVID-19) pandemic has become a global health emergency resulting in high psychological burdens. Along with mental health, sleep often is impaired by stress, although good sleep quality is crucial for the individual well-being. In this study, we explore the relationship between COVID-19- related stress, sleep quality, and symptoms of stress, depression, and anxiety in two different time periods. Method: Therefore, two similar online surveys were conducted, the first, from April to June 2020 in a period with assumed high stress and uncertainty and, a second, in an assumed low-stress period from mid-July to mid-October 2020 in Germany. The following questionnaires were answered by 993 participants (M = 33.7 years, SD = 12.7) in the first and by 641 participants (M = 36.65 years, SD = 12.2) in the second study: COVID-19 Pandemic Stress Scale (CPSS), Pittsburgh Sleep Quality Index (PSQI), and Depression Anxiety Stress Scale (DASS-21). Results: In both surveys, higher COVID-19-related stress was associated with worse sleep quality and higher levels of overall stress but not with depressive symptoms. Interestingly, higher anxiety was only associated with higher levels of COVID-19- related stress in the first study. Descriptively, higher COVID-19-related stress levels were reported in the first study, while participants in the second study reported more impaired health, e.g., worse sleep quality, more stress, and depressive and anxiety symptoms. Conclusions: Our findings indicate that due to the enduring burdens of the pandemic, numbers of sleep problems and mental health problems may further increase, emphasizing the urgent need for large-scaled public interventions.