This third edition of the Textbook of Anxiety Disorders, now entitled The American Textbook of Anxiety, Trauma, and OCD-Related Disorders to reflect the updated categories of DSM-5, provides a review and update on the relevant science and core transdiagnostic and disease specific principles as well as state-of-the-art reviews of psychotherapy and pharmacotherapy treatment approaches and their combinations.The organization of the volume and individual chapters has been retooled for DSM-5. Some chapters have been updated, and some have been completely rewritten. The contributors are a who's who of experts on anxiety, trauma, and OCD-related disorders.For specific conditions, including generalized anxiety disorder, social anxiety disorder, panic and agoraphobia, specific phobia, OCD, and trauma and stressor-related conditions such as PTSD and persistent forms of grief, we include sections on phenomenology, pathogenesis, and treatment. Special sections focus on the issues of comorbidity, as well as specific issues for children and older adults. Transdiagnostic interventions, such as Barlow's Unified Protocol, are included as new chapters.