Vets' PTSD Claims Trigger Study of Diagnostic Criteria

Both popular books and scholarly articles published in recent years have suggested that many cases of PTSD among Vietnam veterans are fabrications falling on oversympathetic, guilt-ridden ears. Other research disputes that conclusion. Speakers for both points of view presented their cases at the IOM meeting.

How widespread is PTSD among Vietnam War veterans? Only 3.5 percent of soldiers reported combat stress reactions during the war, yet the National Vietnam Veterans Readjustment Survey in the mid-1980s found a lifetime incidence of 30.9 percent among men who had served in the war zone and an additional 22.5 percent reporting a subclinical variant, said Richard McNally, Ph.D., director of clinical training in the Department of Psychology at Harvard University. Only 15 percent of all troops sent to Vietnam were assigned to combat units, yet two or three times that percentage appear to have experienced PTSD at some point.

Several hypotheses have been advanced to explain this apparent discrepancy, in addition to simple fabrication of war stories. Sampling errors or interviewer biases may account for some of the difference. Noncombat troops like medics or truck drivers might have been exposed to trauma. To some, mere deployment in a war zone might be considered stressful, even if not traumatic. Or there may be other reasons.

“Perhaps they are imposing a trauma narrative on their lives, attributing their problems to military service,” said McNally. The definition of “trauma” has broadened over the years to include pre- and posttrauma factors and noncanonical stressors, from fender benders to normal childbirth.

“Unlike any other diagnosis in the DSM, PTSD implies an etiology,” said another speaker, Sally Satel, M.D., a psychiatrist affiliated with the American Enterprise Institute, a conservative Washington, D.C., think tank. “Everything else is a constellation of symptoms.”

Satel called PTSD “a fear reaction that is not extinguished after the stimulus is gone for at least 30 days.” She would treat anyone with symptoms but would not agree to a trauma-related diagnosis for events that happened longer than five years before.

The current increase in disability claims may be due to chronic PTSD that has existed since the war or to delayed presentation after earlier symptoms, she said, but PTSD may also serve as a “comforting cultural narrative” for life failure, induced by a “victim culture” or a crutch for “folks who need a retirement plan.”

To the contrary, PTSD has been a useful and valid diagnosis for 25 years, even with minor changes in definition, said Matthew Friedman, M.D., Ph.D., director of the National Center for PTSD.

“PTSD is the inability to cope following overwhelming stress,” he said. “Not everyone exposed gets the symptoms. Why are some vulnerable and some not?”

Usable answers will require triangulation of archival and clinical data, along with self-reported symptoms.

That is the research direction Bruce Dohrenwend, Ph.D., and colleagues have taken. They used military records from 1,200 Vietnam War vets to develop prospective data not based solely on self-reports. Although 15 percent of U.S. troops were assigned to frontline combat units, perhaps 75 percent were exposed to some kind of enemy action: those in defensive positions, artillery and engineering units and others, said Dohrenwend, chief of the Department of Social Psychiatry at the New York State Psychiatric Institute and professor of psychiatry and public health at Columbia University.

For instance, Dohrenwend said at the hearing, “Noncombat troops got 30 percent of Purple Hearts in Vietnam.”

Dohrenwend went back to contemporary records to look at not only each veteran's military history but also the overall monthly killed-in-action (KIA) rate during his time in Vietnam, and the KIA rate in his division and in his company—indicators of exposure to violence. Using the SCID, he tried to separate pre- and postwar traumatic events. He also found no elevation in MMPI scores in veterans with low or moderate combat exposure, which would have indicated dissembling. Few stories appeared to be false after this analysis, he said.

Neither the 30.9 percent PTSD rate nor the 15 percent combat exposure figures reflect reality, said Dohrenwend. “War-related PTSD is lower and combat exposure is higher,” he concluded. An onset rate of 12 percent to 15 percent is more likely, and there is little evidence of dissembling by veterans.

A full explanation of PTSD may involve a combination of wartime threats and individual risk factors, said Terry Keane, Ph.D., of the VA Boston Healthcare System. Actual combat, fear of imminent death, having friends die in one's arms—all occurring in the anxiety-provoking environment of military life—play out against the absence of social support, adverse childhood experiences, low socioeconomic status or educational achievement, and other life stressors, said Keane.

He, too, argued for a tripartite evaluation of suspected PTSD cases that would include clinical diagnostic interviews, psychological testing, and neurobiological tests like brain imaging, EKGs, or neurohormonal assays—none of which is currently diagnostic.

However arrived at, a diagnosis of PTSD should be differentiated from any level of disability it might produce, said Regier, who also spoke at the IOM meeting on behalf of APA.

“We need to separate diagnostic criteria or a diagnosis of PTSD from the level of disability associated with that diagnosis,” he said.“ We also have to consider the patient's suitability for treatment and the course of that treatment along with any disability compensation.”

Further research is needed on reasons that some veterans come to clinical attention only long after exposure to trauma, he said. This is especially true in the armed services, where discussion of psychological aftereffects of trauma may raise career issues or fears of being seen as weak.

Finally, said Regier, the committee will need to examine why only PTSD and not other diagnoses—depression or anxiety—is seen as the route to disability or treatment for veterans.

Whatever the IOM decides regarding PTSD will affect not only veterans of a war three decades in the past but also the young men and women now fighting in the Middle East, said Friedman. “Counterinsurgency is more toxic than invasion, but how this plays out in five, 10, or 15 years is anybody's guess,” he said.

Presentations and statements from the IOM are posted at<www.iom.edu/?id=32937>.▪