Toward a Definition and Differentiation of Secondary Traumatic Stress, Vicarious Trauma, Post-Traumatic Stress, and Compassion Fatigue in Relation to First Responders: An Integrative Literature Review

This integrative review focuses on the psychological effects of direct and indirect exposure to trauma among first responders (firefighters, police investigators, police officers, paramedics, ambulance workers). The aim of this study is to provide conceptual clarification of the various terms used: secondary traumatic stress, vicarious trauma, compassion fatigue, and post-traumatic stress disorder. For this study, six databases were consulted: PsycINFO/ARTICLE; PubMed/Medline; Web of Science; Cochrane; Cairn; ScienceDirect, up to January 2026. To be included, articles had to be published in peer-reviewed scientific journals and concern an adult and professional population. Data extraction followed PRISMA guidelines, and 76 studies were included. Two researchers participated in data extraction and ensured the quality of the articles. The main results revealed conceptual porosity maintained by symptomatic overlaps and the limitations of measurement tools, often designed for other professional categories. The analysis also highlights the central role of organizational constraints in the emergence of trauma, the importance of considering the nature of exposure, cumulative burden, personal experience, and professional role in the study of traumatic responses. Finally, this review calls for exposure to trauma among first responders to be viewed as a public health issue.