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This article originally appeared in the August 2007 Harvard Mental Health Letter and is provided courtesy of Harvard Health Publications.

Rethinking posttraumatic stress disorder

What is a traumatic event, and how does it produce symptoms?

“It could go on for years and years, and has, for centuries,” wrote the author of the Sumerian epic of Gilgamesh in the third millennium, B.C., describing the suffering of a character who survived a violent encounter that killed his friend. That terrifying experiences often have lasting psychological consequences was well known for thousands of years before 1980, when the American Psychiatric Association classified posttraumatic stress disorder (PTSD) as a psychiatric disorder in the third edition of its diagnostic manual (DSM-III). PTSD is one of the few psychiatric conditions to which the manual ascribes a definite cause. Although no one doubts that emotional trauma can have devastating effects, a debate about this diagnosis has been ignited, and changes may be in store.

War is a mother lode of traumatic experiences and the chief source of the concept of PTSD. In the American Civil War, the resulting symptoms were sometimes described as battle fatigue. In the First World War, it was called shell shock, and in the Second World War, combat neurosis or traumatic neurosis. Soldiers in those wars who succumbed to posttraumatic stress were sometimes regarded as weak or inadequate, but that view changed as understanding of their experiences improved. Physicians and mental health professionals came to see the symptoms as, in a sense, normal responses to abnormal circumstances. By the middle of the Korean War, DSM-I included a diagnosis of “gross stress reaction,” and DSM-II described a “transient situational disturbance.”

Establishing the diagnosis

At the time DSM-III was compiled, professionals had begun to emphasize more lasting effects of trauma. We were in the aftermath of the Vietnam War, and some critics of the diagnosis of PTSD have suggested that it served a political purpose, in effect making the case that war is dangerous to mental health. The creators of DSM-III certainly sympathized with the veterans of a war many regarded as unjustified, and they looked for a pattern in the resulting suffering. At the same time, the women’s movement was drawing new attention to the effects of sexual and physical abuse on women and children. All of this history influenced the psychiatric understanding of PTSD.

As the disorder is defined today, it involves three kinds of symptoms:

Hyperarousal. Individuals with PTSD are irritable, easily startled, and constantly on guard. They sleep poorly and have difficulty concentrating.
Re-experiencing or intrusion. They recall the traumatic event involuntarily in the form of vivid memories, nightmares, and flashbacks. They may feel or even act as though it is happening again. Any object, situation, or feeling that reminds them of the trauma may cause intense distress.
Avoidance and emotional numbing. They avoid feelings, thoughts, persons, places, and situations that evoke memories of the trauma. They lose interest in their usual activities. They feel estranged from other people and even from their own feelings.

These three sets of symptoms have a common theme — fixation on the trauma. The traumatic event dominates and controls the lives of people with PTSD. They have not assimilated the experience, so they repeatedly re-experience it in its original terrifying form. They are both emotionally numb and constantly on guard against a danger that no longer exists because they feel desperately conflicting needs for vigilance and repose.

What is a trauma?

In DSM-III, a trauma was defined as an event beyond the range of ordinary human experience, one that would be distressing for almost anyone. Since then the definition has changed. In the present edition of the diagnostic manual, DSM-IV-TR, a “text revision” of the DSM-IV published in 2000, a traumatic experience is defined as one that involves a threat (or reality) of death, serious injury, or damage to physical integrity, and inspires intense fear, helplessness, or horror. The victim may experience the event directly, witness it, or be confronted with it in some other way.

Some have interpreted these changes as shifting the focus away from the traumatic event itself and toward individual responses. The event is no longer necessarily utterly out of the ordinary or one that would be distressing to almost everyone. What arouses intense fear, helplessness, and horror in one person may have little effect on another. And in the DSM-IV-TR description, even immediate experience of the trauma is no longer necessary; being confronted with it could be interpreted to include hearing about it. There is no longer such an intimate relationship between a definite set of symptoms and a distinct kind of experience, so the theme of fixation on the trauma that links the symptoms is no longer so clear.

By the DSM-IV-TR definition, many kinds of events can be described as traumatic and many people can be said to have undergone a traumatic experience. The National Institute of Mental Health’s Epidemiologic Catchment Area study found that more than 60% of men and more than 50% of women in the United States have had such an experience. The vast majority of people who have had a traumatic experience do not develop PTSD — nearly 90% of women and more than 97% of men in one large German study.

In another study, researchers at Duke University interviewed hundreds of children and their parents at yearly intervals from ages 9 through 16, asking about traumatic events and symptoms of PTSD. More than two-thirds of the children had experienced at least one traumatic event, and a third had experienced more than one. The most common was witnessing or learning about a trauma suffered by another person. Only 13% reported any symptoms typical of PTSD, and fewer than 1 in 200 had PTSD itself.

Just as trauma only occasionally causes PTSD symptoms, the symptoms associated with this diagnosis are not always the result of trauma. Some research suggests that people who experience “normal” stresses like illness, divorce, bereavement, or job loss develop such symptoms at the same rate as those who undergo traumatic stress. In a questionnaire survey of 600 undergraduates at Temple University, about 70% reported having had an experience they regarded as traumatic. About half of these events — for example, a romantic breakup or the anticipated death of a relative — were not traumatic by DSM-IV-TR or most other standards. But students who had had these apparently milder experiences reported just as much distress as those who suffered a catastrophic trauma.

Effects of gender

It has become clear that people who develop PTSD differ from those who don’t in a number of ways unrelated to the nature of the traumatic experience itself. To begin with, women seem to be two to three times as susceptible as men. They may be more biologically vulnerable for genetic or hormonal reasons. They also tend to undergo different kinds of trauma. Men suffer more non-sexual physical violence, women more rape and childhood sexual abuse. It is possible that female trauma is more often prolonged — the battered wife versus the street fighter, for example — and long-term stress can have more profound effects than single events. But even when both sexes have the same experience, women are more likely to develop PTSD. Six months after the bombing of the federal building in Oklahoma City, 45% of women exposed to the bombing had the disorder, and only 23% of the men did.
Differences in social support may be a factor; for example, wives may be better at soothing husbands than the other way around. Maybe women are more willing to admit that they have the symptoms and seek help, instead of retreating into solitary misery or disguising their problems with drinking and aggression. In a survey of 10,000 Australians, women reported the following traumatic symptoms more often than men did: avoiding thoughts and feelings related to a trauma, disturbed sleep, and intense startle reactions. Men reported one symptom more often than women did — emotional and social withdrawal.

Other individual differences

Many other individual differences influence vulnerability. PTSD is more likely to arise in someone who has suffered previous traumatic experiences. Intentional injury — physical or sexual assault — creates a greater risk of PTSD than a natural disaster or an accident. The risk is even higher for victims who feel guilty because they believe that they bear some responsibility for the event. High IQ may blunt the impact of a traumatic experience on mental health, and low IQ may exacerbate it.

Depression, anxiety, alcohol and drug abuse, childhood behavior disorders and adolescent delinquency, antisocial personality, and other personality disorders also heighten vulnerability to PTSD. German researchers interviewed a group of firefighters — for whom PTSD is an occupational hazard — immediately after their basic training and again periodically for two years. They found that men who showed more hostility and less confidence in their own abilities were more likely to develop PTSD symptoms.

Twin and adoption studies suggest that heredity is a factor. In one study of identical twins, only one of each pair was a Vietnam combat veteran. About half of the veterans had been diagnosed with PTSD. Tests revealed subtle deficiencies in cognitive functioning that distinguished them from veterans who did not develop PTSD. But their identical twins who had not been in combat had the same deficiencies — which suggests that these were risk factors for PTSD rather than consequences of the traumatic experience.

Surprisingly, there is even some evidence that what happens to a person after the traumatic event influences the chance of developing PTSD as much as or more than what happens before. And we tend to revise our description of experiences in the light of later symptoms. In a study of veterans of the first Iraq war, 70% recalled a traumatic experience two years after returning but not after a month. Most veterans remembered more such experiences as time passed, especially the kind that did not involve a direct threat of death or physical injury to themselves.

Because memory is malleable and events before and after the trauma have so much influence on it, there is a risk that symptoms with other causes will be mistakenly attributed to a traumatic event. Many disability claims for PTSD have been made recently by Vietnam-era veterans whose service ended in the 1970s. Critics point out that there are many reasons why people might want to make sense of their problems by ascribing them to a long-past experience. These critics fear that researchers and practitioners are not being careful enough to distinguish possible “pseudo-PTSD” from the real thing.

A distinctive diagnosis?

The symptoms of PTSD overlap with the symptoms of other psychiatric disorders, especially depression and anxiety. In a Duke University study of children and adolescents, for example, being exposed to trauma did not result in PTSD symptoms but nearly doubled the rate of other psychiatric disorders. Researchers at Harvard studying men and women who volunteered for a study of depression found that by DSM-IV-TR standards, nearly 80% had undergone a traumatic experience and many also formally fit the diagnosis of PTSD.

Australian psychologists tried to disentangle PTSD and depression among more than 350 people with serious injuries resulting from traffic accidents. Three months after the accident, 4% to 12% were diagnosed with PTSD, and another 16% to 30% were diagnosed with both PTSD and depression. In half of these patients, the diagnosis shifted from PTSD to depression or the other way around in the course of a year. The researchers suggest that PTSD symptoms are difficult to single out in reactions to traumatic stress.

References

Breslau N, et al. “Intelligence and Other Predisposing Factors in Exposure to Trauma and Posttraumatic Stress Disorder: A Follow-Up Study at Age 17 Years,” Archives of General Psychiatry (November 2006): Vol. 63, No. 11, pp. 1238–45.

Gold SD, et al. “Is Life Stress More Traumatic Than Traumatic Stress?” Journal of Anxiety Disorders (2005): Vol. 19, No. 6, pp. 687–98.

Lasiuk GC, et al. “Post Traumatic Stress Disorder Part II: Development of the Construct within the North American Psychiatric Taxonomy,” Perspectives in Psychiatric Care (May 2006): Vol. 42, No. 1, pp. 72–81.

McHugh PR, et al. “PTSD: A Problematic Diagnostic Category,” Journal of Anxiety Disorders (2007): Vol. 21, No. 2, pp. 211–22.

Nemeroff CB, et al. “Posttraumatic Stress Disorder: A State-of-the-Science Review,” Journal of Psychiatric Research (February 2006): Vol. 40, No. 1, pp. 1–21.

Rosen GM, et al. “Pseudo-PTSD,” Journal of Anxiety Disorders (2007): Vol. 21, No. 2, pp. 201–10.

Spitzer RL, et al. “Saving PTSD from Itself in DSM-V,” Journal of Anxiety Disorders (2007): Vol. 21, No. 2, pp. 233–41.

Changes in store

As a result of the many questions raised by research, experts are reconsidering how to describe traumatic stress, PTSD symptoms, and the relationship between them. The fifth edition of the American Psychiatric Association’s diagnostic manual may put less emphasis on the diagnosis of PTSD and more on a range of responses that depend on much besides the traumatic event alone. In the future, research may concentrate more on individual vulnerability and the lives of patients before and after the experience. With more long-term studies beginning immediately after an event, relying too much on memory may no longer be necessary.

For now, it is important to remember that not all traumas are alike, that any trauma will affect different people differently, and that PTSD should not necessarily be the default diagnosis when symptoms appear after any particular traumatic experience. But however present controversies are resolved, the knowledge consolidated in the last century will not be lost — that traumatic events are a threat to mental health, that the effects can be lasting, and that sufferers often need and deserve help.