This article provides an overview of the process of developing the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) of the American Psychiatric Association with a focus on issues related to the trauma-related disorders, particularly the dissociative disorders (DD). We also discuss the highlights of research within the past 5 years in the assessment, treatment, and neurobiological basis of trauma disorders. Recent research shows that DD are associated with severe symptoms as well as a higher rate of utilization of mental health treatment compared with other psychiatric disorders. As a result, DD, like other complex posttraumatic disorders, exact a high economic as well as personal burden for patients and society. The latest research indicates that DD patients show a suboptimal response to standard exposure-based treatments for posttraumatic stress disorder as well as high levels of attrition from treatment. An emerging body of research on DD treatment, primarily of naturalistic and open trials, indicates that patients who receive specialized treatment that addresses their trauma-based, dissociative symptoms show improved functioning and reduced symptoms. Recent studies of the underlying neurobiological basis for dissociation support a model of excessive limbic inhibition in DD that is consistent with the phenomenology and clinical presentation of these patients. We are optimistic that the forthcoming DSM-5 will stimulate research on dissociation and the DD and suggest areas for future studies.