The COVID-19 pandemic has provoked generalized uncertainty around the world, with health workers experiencing anxiety, depression, burnout, insomnia, and stress. Although the effects of the pandemic on mental health may change as it evolves, the majority of reports have been web-based, cross-sectional studies. We performed a study assessing acute stress in frontline health workers during two consecutive epidemic waves. After screening for trait anxiety/depression and dissociative experiences, we evaluated changes in acute stress, considering resilience, state anxiety, burnout, depersonalization/derealization symptoms, and quality of sleep as cofactors. During the first epidemic wave (April 2020), health workers reported acute stress related to COVID-19, which was related to state anxiety. After the first epidemic wave, acute stress decreased, with no increase during the second epidemic wave (December 2020), and further decreased when vaccination started. During the follow-up (April 2020 to February 2021), the acute stress score was related to bad quality of sleep. However, acute stress, state anxiety, and burnout were all related to trait anxiety/depression, while the resilience score was invariant through time. Overall, the results emphasize the relevance of mental health screening before, during, and after an epidemic wave of infections, in order to enable coping during successive sanitary crises.

In addition to the sanitary constrains implemented due to the pandemic, frontline physicians have faced increased workloads with insufficient resources, and the responsibility to make extraordinary clinical decisions. In 108 physicians who were at the forefront of care of patients with COVID-19 during the first two years of the pandemic, mental health, moral distress, and moral injury were assessed twice, in between two late waves of COVID-19 contagions, according to their adverse psychological reactions, in-hospital experience, sick leave due to COVID-19, quality of sleep, moral sensitivity, clinical empathy, resilience, and sense of coherence. Three months after the wave of contagions, the adverse emotional reactions and moral distress decreased, while moral injury persisted. Moral distress was related to clinical empathy, with influence from burnout and sick leave due to COVID-19, and moral injury was related to the sense of coherence, while recovery from moral distress was related to resilience. The results suggest that measures to prevent physician infection, as well as strengthening resilience and a sense of coherence, may be helpful to prevent persistent mental damage after exposure to a sanitary crisis.