INTRODUCTION AND DIAGNOSIS OF POSTTRAUMATIC STRESS DISORDER
The impact of traumatic events and the behavioral sequelae associated with them has been recognized for over 100 years under a variety of different labels, including compensation neurosis, nervous shock, hysteria, and war neurosis. The introduction of posttraumatic stress disorder (PTSD) into the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM–III in 1980 (APA, 1980) and its placement among the anxiety disorders reflects the perception that anxiety is a core component of an individual's reaction to a traumatic experience. Accordingly, PTSD is an anxiety disorder that develops in some individuals after a traumatic event defined by the DSM–IV (APA, 1994) as (1) experiencing, witnessing, or being confronted with an event that involves actual or threatened death or injury, or a threat to their physical integrity or that of others, and (2) responding to the event with intense fear, helplessness, or horror.
In addition to experiencing or witnessing a traumatic event, a diagnosis of PTSD requires the individual to meet the following three symptom criteria: (1) At least one reexperiencing symptom, such as distressing recollections of the trauma, distressing dreams of the event, reliving the experience through flashbacks, psychological distress at exposure to internal or external reminders of the event, or physiological reactivity to those trauma reminders. (2) At least three symptoms of persistent avoidance such as making an effort to avoid trauma-related thoughts or feelings, making an effort to avoid trauma-related activities or situations, amnesia for important aspects of the event, diminished interest in activities, detachment from others, restricted range of affect, or a sense of a foreshortened future.