Iraq isn't the only reason Vietnam veterans are pouring in to the Department of Veterans Affairs for help for post-traumatic stress disorder decades after the war.
While there is no empirical study examining the reasons for the large increase in PTSD cases decades after the Vietnam war, experts say a lot of hypotheses have been formed. Some of the hypotheses are based on studies that offer pieces of a puzzle. Some experts cite aging and demographics as potential reasons for the recent influx.
Ira Katz, head of the U.S. Department of Veterans Affairs mental health programs, said that many Vietnam vets might have been coping with mild or moderate post-traumatic stress symptoms throughout their lives.
"And they've lost the ability to deal with them, as their health has become affected," Katz said, "as workaholics have retired, or they've lost friends or husbands or wives."
Katz said another theory has to do with the aging brain.
"As brain changes occur later in life, the ability to keep the symptoms under control, from a neural perspective, may have been affected," Katz said.
Rich McNally is a psychologist at Harvard who helped redefine the signs of PTSD for the Diagnostic and Statistical Manual of Mental Disorders. McNally said at least some veterans may be diagnosed with PTSD when they really have depression or panic disorder.
McNally said it is possible that some veterans are exaggerating trauma histories, PTSD symptoms, or both, to obtain service-connected disability compensation.
Epidemiologist Bill Schlenger is a principal author of the National Vietnam Veterans Readjustment Study, a study of the prevalence of PTSD and other psychological effects of the war on Vietnam veterans.
Schlenger said any system with financial compensation attached to it is going to draw some people who try to take advantage of it. But, he said, "The overwhelming evidence from epidemiologic studies of Vietnam veterans is that that's a relatively minor problem."
Schlenger said the facts of those veterans' lives are likely a bigger factor.
"They're getting older, their children have grown up and gone, sometimes even their grandchildren have grown — and they're nearing or have already retired. So there's less going on in their life to distract them from their combat experience and what happened to them," Schlenger said. "The hypothesis goes, when one is less distracted, it's harder to contain the intrusion."
John Wilson, a psychologist at Cleveland State University and an expert on PTSD and Vietnam veterans, said he doesn't buy the idea that aging and retirement are major factors in and of themselves. He said he believes the war in Iraq is a major factor.
Wilson said he does know how things get revisited. For example, he notes that when Stephen Spielberg's movie Saving Private Ryan was released, World War II veterans flooded the VA for help.
"It got to the point where the VA had to create a crisis line for vets having flashbacks of their war experiences," Wilson said.
These veterans may have been approaching the end of their lives, but it's not only the issue of aging, Wilson said.
"There's the whole question of meaning. There are more existential questions about the meaning of life, the meaning of sacrifice, the meaning of what the war did to one's life," Wilson said. "In my experience with Vietnam veterans, there's not a day that goes by that they don't think about the war."
When you combine the issue of aging, Wilson said, "The search for meaning of life at this age, and the rekindling of questions about one's own war experiences because of what's going on in Iraq, you have a kind of a perfect storm to aggravate the questions of, What's this all about, anyway?"