New look at Vietnam vets' PTSD data

A report published Friday in the journal Science has found "very little evidence of falsification" by Vietnam veterans with Post-Traumatic Stress Disorder. The researchers selected a sample of 260 participants from the 1988 National Vietnam Veterans Readjustment Study (based on data from surveys of 1,200 veterans) and used military records to verify traumatic events reported by the veterans.

The authors of the new study also found rates of PTSD that differed from the NVVRS estimates. The NVVRS found that 15.2 percent of veterans had PTSD at the time of the study; 30.9 had PTSD at some point during their lifetime. The new analysis finds 9.1 percent with a "current" diagnosis and 18.7 percent with a "lifetime" diagnosis.

Dr. Matthew J. Friedman, executive director of the National Center for Post-Traumatic Stress Disorder for the Department of Veterans Affairs (and a member of the Dart Center advisory council), told New York Times reporter Benedict Carey that "We can quibble about the numbers but the point is that it’s a lot of people." Harvard psychologist Richard McNally--a long-time and outspoken critic of the NVVRS estimates--said that the new numbers "should not be used as a justification for short-changing services that are needed to help veterans." (Click here for an NPR report about the new study.)

UPDATE (Friday, 11:30 am): The study (subscription required) goes a long way toward refuting critics who claim that the NVVRS PTSD-prevalence estimates are inflated by the fraudulent claims of benefit-seeking veterans. Using military records, military histories and newspaper accounts, the authors report that they were able to confirm "the exposure to traumatic stressors of most of the subsample veterans."

The authors also examined the "conundrum" frequently cited by critics of the NVVRS: only 15 percent of troops in Vietnam were classified as having "combat exposure" but 30.9 percent eventually had PTSD. The authors were able to establish that "non-combat" soldiers in Vietnam were, in fact, exposed to significant, verifiable stressors. The authors found a strong relationship (stronger than was identified by the NVVRS, in fact) between PTSD symptoms and exposure to war-zone stressors, which the authors note is a "relationship that cannot be due to biases in self-reports of exposure."

The authors also address the disparity between the PTSD prevalence figures of the NVVRS and those of the Centers for Disease Control study, which "reported rates of 14.7% lifetime PTSD and 2.2% current PTSD 11 to 12 years after the Vietnam war ended." This disparity, the authors say, is not due to flaws in the NVVRS (as critics have contended) but because the CDC used a partial version of a survey that has since been found to underestimate PTSD. The authors explain:

The CDC used about half of the items from a newly developed module from the Diagnostic Interview Schedule (DIS) to diagnose lifetime and current PTSD on the basis of responses to closed questions asked by lay interviewers. This version of the DIS PTSD module has been found to diagnose much lower rates of PTSD in the general population than the other diagnostic instrument that is most widely used by lay interviewers. Against this background, it is not surprising that the abbreviated CDC adaptation of the DIS PTSD module was found in the NVVRS to miss 78% of veterans who had diagnosable PTSD, according to the SCID clinicians. These results suggest that PTSD is under-diagnosed in both military and civilian samples when this version of DIS PTSD is used.

The authors conclude:

The message from the NVVRS has been that the Vietnam War took a severe psychological toll on U.S. veterans. Our results provide compelling reasons to take this message seriously.

UPDATE 2 (Friday, 3:00 pm): Why are the rates of PTSD in this new study lower than the NVVRS rates?

Seven veterans with PTSD were removed from the sample group: "four veterans with prewar onset, two missing onset information, and one missing sampling weight." Once these seven were removed from the analysis, "unadjusted" rates of PTSD were found (22.5 percent "lifetime"; 12.2 percent "current"). Then, these rates were adjusted for "impairment of functioning" (the current criteria require that symptoms cause a certain level of impairment before PTSD can be diagnosed; the criteria in place at the time of the NVVRS did not) and "documentation of exposure" (eight veterans in the sample group with PTSD reported stressors that could not be confirmed by independent sources; of these eight, the authors write, "Record information was contradictory for only two").

One point likely to be noted by critics of this study is the exclusion of veterans with prewar onset of PTSD. A prewar diagnosis doesn't necessarily invalidate a war-time stressor. The authors do not reveal whether those veterans' re-experiencing symptoms (nightmares, flashbacks) are of the prewar trauma, or of the war-zone trauma. If the nightmares and flashbacks of a veteran with a prewar diagnosis were mainly of war-time stressors, it would be hard to say that veteran's PTSD was not "war-related."

UK to pardon "Shot at Dawn" soldiers

In the early years of World War One, "Shell Shocked" soldiers were thought to be suffering physical damage to the brain or nervous system brought on by the atmospheric force of exploding shells. After study, however, mental health practitioners realized that most victims of "Shell Shock" were in fact suffering a psychological disorder brought on by the stress of combat. It was also deduced that many soldiers charged with cowardice or desertion were also suffering a combat stress reaction.

The development of this understanding--along with new, more effective treatment methods--was of great benefit to soldiers in the Allied armies during the last years of the war. But these discoveries came too late for the 306 British soldiers executed (shot at dawn) for cowardice or desertion during the Great War.

Now, after a long campaign by families of the victims, the British government has announced that it will posthumously pardon the 306 soldiers. Des Browne, the Secretary of Defence, said in a statement: "Although this is a historical matter, I am conscious of how the families of these men feel today. They have had to endure a stigma for decades. That makes this a moral issue too, and having reviewed it, I believe it is appropriate to seek a statutory pardon."

For more about the history of combat stress and military psychiatry, read "Psychiatric Lessons of War," the first chapter of the Army's War Psychiatry textbook.

Studies probe post-tsunami mental health

Are depression, anxiety and Post-Traumatic Stress Disorder useful concepts when applied to non-Western cultures? Or are they--as some critics have contended--simply Western cultural constructs?

Two studies recently published in the Journal of the American Medical Association offer the beginnings of an answer to these questions.

One study focused on post-tsunami mental health reactions among adults, the other study looked at children.

In an accompanying commentary, Derrick Silove and Richard Bryant note that "The ongoing controversy risks confusing funding agencies and other donors, as well as those responsible for planning mental health programs as part of humanitarian relief efforts following disasters." The two studies, Silove and Bryant write:

... add to a growing body of research indicating that PTSD symptoms can be identified both in adults and in children across cultures. The key question, however, is whether the prevalence of PTSD symptoms in the immediate aftermath of disasters offers valid information and reliable direction to guide local mental health planning.

Both studies identify cultural factors may help people cope with trauma. In the study of adults, the authors write:

The Buddhist component of the Thai belief system, for instance, contemplates that life is to a certain extent predetermined and the result of one's own actions or karma. This belief may help Buddhists accept and overcome negative events occurring during the course of their lives, which would be consistent with findings from other studies showing a protective effect of the Buddhist religion on anxiety and depression.

Another aspect of the Thai belief system is the notion that every space, be it air or water, has a ruler or spirit, a supernatural power that governs the space. For individuals to share the space, the ruler needs to be informed and pleased and its territory must be respected. Anecdotal conversations with tsunami survivors indicate that many individuals believe that overfishing and exploitation of the sea were causes of the tsunami, a revenge of the spirits of the sea. The notion of carrying a certain responsibility for the occurrence of the tsunami may make it easier to accept and cope with its consequences.

In the survey of adults, about 10 percent reported seeing a ghost after the tsunami. The authors explain:

Reports of seeing or hearing ghosts are common among rural Thais and are not confined to periods of disaster or specific events but are a normal part of Thai culture and beliefs. Hence, in most cases this phenomenon should be interpreted in the context of the local belief system and as a culturally specific way of coping with death and reincarnation rather than a symptom of mental illness.

Study: War can affect brain function

A study published in the Journal of the American Medical Association this week finds that, in some Army veterans, deployment to the Iraq War is associated with increased confusion and tension, a shortened attention span, and impaired memory. The study, led by Jennifer Vasterling of the Southeast Louisiana Veterans Health Care System, also found that combat veterans had faster reaction time compared to Army personnel who hadn't served in Iraq. (News coverage here: LA Times, Psychiatric Times.)

In an accompanying editorial, Matthew Hotopf and Simon Wessely note that the neurological changes cited above are described by the researchers as "mild" and "subtle."

Hotopf and Wessely suggest that the findings support the conception of post-deployment mental health problems as "the persistence on return home of some of the psychological adaptations required during deployment." They write:

The term battlemind captures the way in which deployed military personnel develop ways of adapting that are appropriate and helpful when vigilance is required, decisions have to be taken quickly, targeted aggression is appropriate, and emotional control is essential. Many returning veterans report difficulties switching from these normal responses to the responses required at home. The finding that veterans had improved reaction times provides a clue: it would be unlikely for a pathological process caused by neurotoxins to improve reaction time. Continued hypervigilance provides a more plausible explanation. The nature of the scores that changed on the Profile of Mood States is another clue in that veterans experienced an increase in anxiety symptoms (feeling "tense" or "on edge") as well as confusion (feeling "bewildered" or "muddled"). Although these phenomena may have some similarities to PTSD, they are perhaps better considered as essentially normal coping experiences, which may perhaps influence neuropsychological function.