Grounded in the updated Posttraumatic Stress Disorder Prevention and Treatment Guidelines of the International Society for Traumatic Stress Studies (ISTSS), the third edition of this definitive work has more than 90% new content. Chapters describe PTSD assessment and intervention practices that have been shown to work and provide practical, real-world implementation guidance. Foremost authorities address the complexities of trauma treatment with adults, adolescents, and children in diverse clinical contexts. The book delves into common obstacles and ways to overcome them, when to stop trying a particular approach with a client, and what to do next. Special topics include transdiagnostic interventions for PTSD and co-occurring problems, dissemination challenges, and analyzing the cost-effectiveness of treatments. Prior edition editors: Edna B. Foa, Terence M. Keane, Matthew J. Friedman, and Judith A. Cohen. New to This Edition*Fully rewritten to reflect over a decade of clinical, empirical, and theoretical developments, as well as changes in DSM-5 and ICD-11.*Increased research-to-practice focus--helps the clinician apply the recommendations in specific clinical situations.*New chapters on previously covered treatments: early interventions, psychopharmacotherapy for adults and children, and EMDR therapy.*Chapters on additional treatments: prolonged exposure, cognitive processing therapy, cognitive therapy, combined psychotherapy and medication, e-mental health, and complementary and alternative approaches.*Chapters on cutting-edge topics, including personalized interventions and advances in implementation science.