ABSTRACT The COVID-19 pandemic has imposed a health crisis around the world. Health professionals are frequently exposed to stressors that put them at high risk for the development or progression of disabling mental disorders, including posttraumatic stress disorder (PTSD). To understand how pandemic stressors have affected the mental health of healthcare workers, our group conducted a longitudinal and nationwide survey. We investigated the occurrence of traumatic events related to the COVID-19 pandemic and the association between exposure to these events and PTSD symptomatology. Importantly, we also investigated factors that might increase or decrease the risk for PTSD. Depression symptoms were also investigated. The results of the first wave of the project were published in a series of three articles, each focused on different risk or protective factors. The results showed that female sex, young age, a lack of adequate personal protective equipment, social isolation and a previous history of mental illness were consistent predictors of PTSD symptoms. Healthcare workers who reported high levels of peritraumatic tonic immobility, a defensive response that is involuntary, reflexive, and evoked by an intense and inescapable threat, also exhibited an increase in the probability of being diagnosed with PTSD. On the other hand, professional recognition had a negative relationship with PTSD and depression symptoms, emerging as a significant protective factor for psychological health. The identification of protective and risk factors in these situations is crucial to guide the adoption of long-term measures in work environments that will enhance the psychological health of these professionals.