POSTTRAUMATIC STRESS DISORDER
It has long been known that traumatic events can have profound effects on memories, cognitions, emotions, and behaviors. However, despite abundant evidence for persisting and sometimes disabling psychological sequelae of exposure to extreme stressors, the evolution of posttraumatic stress disorder (PTSD) as a modern diagnosis is relatively recent. PTSD-like disorders were described in the U.S. Civil War (DaCosta's syndrome, irritable heart of soldiers), following railroad accidents in the late nineteenth century (Railway Spine), and as the tragic consequence of World Wars I and II (shell shock, traumatic neurosis, neurasthenia, survivor syndrome).
In the 1950s and 1960s, debate revolved around the issue of whether there was anything unique about the psychiatric symptoms that emerged following extreme stress relative to psychiatric symptoms that were expressed in the context of the stresses of everyday life. Thus, the diagnosis of Gross Stress Reaction appeared in the initial Diagnostic and Statistical Manual of Mental Disorders (DSM), but was excluded from DSM-II. In 1980, in the wake of clinical research on soldiers of the Vietnam War, studies of victims of physical and sexual assault, and victims of natural disasters, the American Psychiatric Association introduced PTSD diagnostic criteria in a form that is fundamentally similar to current diagnostic schemata. Unlike other disorders, PTSD is predicated on the occurrence of at least one discrete external event, namely a precipitating trauma. DSM-III defined a trauma as "experiencing an event that is outside the range of usual human experience." However, subsequent epidemiologic studies found that traumatic events are common, that greater than half of the population experienced trauma sometime during their life, and that even witnessing trauma could be predictive of PTSD. The DSM-IV-TR stipulated two subcriteria—one objective, one subjective—to meet formal diagnosis of PTSD: (A1) the person experienced, witnessed, or was confronted with an event or events that involved actual or threatened death or serious injury, or a threat to physical integrity of self or others; and (A2) the person's response involved fear, helplessness, or horror. The change in the definition of a traumatic event from DSM-III to DSM-IV resulted in higher rates of PTSD in a number of epidemiologic studies. The fiscal year 2005 report from the Veterans Benefits Administration indicated that PTSD was the costliest diagnosis for the VA, and the third most frequently claimed disability, making up 4.2% of all claims. The DSM-5 removed subcriterion A2, rendering individual response to traumatic events irrelevant to diagnosis. Moreover, with DSM-5, PTSD is no longer considered an anxiety disorder and is listed under a new category of Stress and Trauma-Related Disorders.
1. Extreme stress exposure
A majority of Americans have been exposure to at least one potentially traumatic (Criterion A) event. The National Comorbidity Study (NCS) surveyed 5877 Americans (2812 men and 3065 women) aged 15–54 years and reported that 60.7% ...