Stress Syndromes

Patterns of Stress-Related Disorders

The most well-known, stress-related psychiatric disorder is post-traumatic stress disorder (PTSD), which can follow exposure to traumatic events and involves a set of characteristic symptoms, including persistent re-experiencing of the event via flashbacks and distressing dreams; avoidance of stimuli associated with the event, expressed as an inability to talk about experiences related to the trauma; numbing of general responsiveness, such as subjective loss of strong or loving feelings; and recurrent symptoms of increased arousal, such as difficultly sleeping or an exaggerated startle reflex. In order to qualify for PTSD under the current (fourth) version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR), one must witness, be confronted with, or personally experience an event that involves actual or threatened death or serious injury, or other threat to the physical integrity of oneself or others. This definition of trauma is broader than its earlier (DSM-III-R) counterpart, which required that the event be outside the range of “usual” human experience, a term that was narrower in scope, albeit hard to define. In DSM-IV-TR, however, a large range of experiences can qualify, such as physical or sexual assault, military combat, natural disasters, a terrorist attack, or more common events such as a car accident or the death of a loved one.

In order to qualify for a PTSD diagnosis, one must not only experience such an event, but must also react to the event with extreme fear, helplessness, or horror and must present with sufficient symptoms for at least one month. Should symptoms be evaluated less than one month after the traumatic event has occurred, a diagnosis of acute stress disorder may be given, which can be changed to PTSD if criteria are still met for the disorder one month after the event terminated. The diagnostic criteria for acute stress disorder are similar, but not identical to, those of PTSD. For either disorder, symptoms must be severe enough to cause significant impairment in interpersonal, occupational, or another area of functioning (e.g., marital problems, or job loss).

Lifetime prevalence estimates of PTSD are around 8 percent, although the likelihood of developing PTSD varies by a number of factors. The best predictor of the development of PTSD is the number of opportunities for exposure to traumatic events, which varies widely among individuals. For example, police officers are exposed more often to trauma than people in other jobs. Supporting this finding, studies of at-risk populations (such as war veterans) have found higher (up to one-third to one-half) lifetime rates of PTSD than general population samples. Proximity to and intensity of the traumatic event also impact the likelihood of developing the disorder. Females are twice as likely as men to develop PTSD, and a family history (probably at least partly genetically based) may be related to this risk. Despite all of the factors that increase risk for PTSD, most individuals exposed to trauma do not develop the disorder. Although it is common to experience individual symptoms, PTSD (and other psychiatric disorders) represent extreme and nonnormative responses to stress.

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