An anxiety disorder in some individuals who have experienced an event that poses a direct threat to the individual's or another person's life. The characteristic features of anxiety disorders are fear, particularly in the absence of a real-life threat to safety, and avoidance behavior.
A diagnosis of posttraumatic stress disorder requires that four criteria be met. First, the individual must have been exposed to an extremely stressful and traumatic event beyond the range of normal human experience. Second, the individual must periodically and persistently reexperience the event. This reexperiencing can take different forms, such as recurrent dreams and nightmares, an inability to stop thinking about the event, flashbacks during which the individual relives the trauma, and auditory hallucinations. Third, there is persistent avoidance of events related to the trauma, and psychological numbing that was not present prior to the trauma. Fourth, enduring symptoms of anxiety and arousal are present. These symptoms can be manifested in different forms, including anger, irritability, a very sensitive startle response, an inability to sleep well, and physiological evidence of fear when the individual is reexposed to a traumatic event.
Posttraumatic stress disorder symptoms appear to range over a continuum of severity, and it is unlikely that the disorder is an all-or-nothing phenomenon. The degree of the posttraumatic stress response is likely to be influenced by a complex interaction of personality, nature of the trauma, and posttraumatic events.
Physiological arousal responses in individuals with posttraumatic stress disorder include increases in heart rate, respiration rate, and skin conductivity upon reexposure to traumatic stimuli. Posttraumatic stress disorder may also be associated with structural and physiological changes in the brain. Stressful events also affect the activity level of the pituitary and adrenal glands. All these physiological changes are probably complexly related to the persistence and waxing and waning of symptoms in posttraumatic stress disorder. In addition, extreme and prolonged stress is associated with a variety of physical ailments, including heart attacks, ulcers, colitis, and decreases in immunological functioning. See Neurobiology
When an individual is diagnosed as having this disorder, particularly after it has been present for a number of years, it is common to also find significant depression, generalized anxiety, substance abuse and dependence, marital problems, and intense, almost debilitating anger. Although the primary symptoms of posttraumatic stress disorder are quite amenable to psychological treatment efforts, these secondary problems commonly associated with the chronic disorder are more difficult to treat.
Posttraumatic stress disorder can be treated by pharmacological means and with psychotherapy. Most psychological treatments for the disorder involve reexposure to the traumatic event. This reexposure is typically imaginal and can range from simply talking about the trauma to having the person vividly imagine reliving the traumatic event. This latter behavioral procedure is called implosion therapy or flooding. While flooding is not appropriate for all posttraumatic stress disorder cases, the procedure can dramatically decrease anxiety and arousal, intrusive thoughts, avoidance behavior, and emotional numbing. Along with specific behavior interventions, individuals with posttraumatic stress disorder should become involved in psychotherapeutic treatment for secondary problems. See Noradrenergic system, Psychopharmacology, Stress (psychology)