Recognizing the cumulative burden of childhood adversities transforms science and practice for trauma and resilience.

The Adverse Childhood Experiences (ACEs) studies transformed our understanding of the true burden of trauma. Notable elements of Felitti and colleagues' findings include the influence of adversity on many physical as well as psychological problems and the persistence of impacts decades after the traumas occurred. In this article, we make the case that the most revolutionary finding was the discovery of a strong dose-response effect, with marked increases in risk observed for individuals who reported four or more adversities. Over the past two decades, our understanding of the cumulative burden of trauma has expanded further, with recognition that experiences outside the family, including peer victimization, community violence, and racism, also contribute to trauma dose. Recent research has provided evidence for the pervasiveness of trauma, which we now realize affects most people, even by the end of adolescence. Extensive scientific evidence has documented that more than 40 biopsychosocial outcomes, including leading causes of adult morbidity and mortality, are associated with adverse childhood experiences, measured by dose. We summarize the state of science and explain how ACEs built a movement for uncovering mechanisms responsible for these relationships. Perhaps unexpectedly, the pervasiveness of trauma also expands our understanding of resilience, which is likewise more common than previously recognized. Emerging research on positive childhood experiences and poly-strengths suggests that individual, family, and community strengths may also contribute to outcomes in a dose-response relationship. We close with an agenda for research, intervention, and policy to reduce the societal burden of adversity and promote resilience. (PsycInfo Database Record (c) 2021 APA, all rights reserved).