The Epidemiology of Trauma and PTSD

Our primary purpose in this chapter is to review findings regarding the prevalence of trauma exposure and PTSD. Methodological progress and evolving definitions have significantly influenced epidemiological findings; thus, we begin this chapter by reviewing these methodological and definitional changes. We next describe what is currently known about the epidemiology of PTSD based on research results, including what is known about trauma exposure and a review of findings for PTSD, including lifetime, chronic, current, and subsyndromal forms of the disorder. In summarizing findings for trauma exposure and PTSD, we begin with studies of adult men and women in "Western" or developed countries; these studies comprise the bulk of the literature and have shaped mainstream thought. We then examine age trends in the results, then review findings for American minorities and populations in developing or non-Western countries. This organization helps to clarify the generalizability of current findings and to identify populations that have not been studied. We conclude this chapter by speculating on the challenges for future epidemiological research.