Posttraumatic stress disorder: from neurobiology to clinical presentation

Posttraumatic stress disorder (PTSD) is a chronic, disabling, and prevalent anxiety disorder. It is triggered by exposure to a psychologically traumatic event, yet only a minority of those exposed actually develop the disorder. Trauma characteristics, as well as genetic, biological, and psychosocial risk factors, contribute to the occurrence of PTSD among survivors of traumatic events. PTSD, therefore is a prime example of gene-environment and psycho-biological interaction. There is a large amount of research in animals on the effects of stress on neurobiology. This has been translated into clinical neuroscience research in PTSD patients. The overarching goal is for our understanding of the neurobiology of the stress response and the long-term effects of stress on stress-responsive systems to inform treatment approaches to PTSD patients. The chapters in this volume, from researchers in all areas of the stress field, including basic scientists as well as research and clinical psychologists and psychiatrists, illustrate the advances in the field that have continued to move from neurobiology to treatment of PTSD. This chapter serves as an introduction to the volume and gives a broad overview of the field. Posttraumatic stress disorder was first recognized as a distinct psychiatric disorder in the third edition of the American Psychiatric Association’s (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM-III; APA, 1981). Subsequent studies have established – and slightly modified – the disorder’s symptom structure, evaluated its natural course, and assessed the disorder’s biological features. The DSM-IV-TR has been in use for many years, and PTSD symptoms based on that are shown in Box 1.1; however, recently the DSM-5 was released (APA, 2014), and the changes from DSM-IV-TR are described later in this chapter.