For many, post-traumatic stress disorder, or PTSD, may be an abstract concept -- yet another statistic by which to measure the impacts of the wars in Iraq and Afghanistan.
But for Lydia Pace, president of the Gulf War Veterans of Arkansas, the effects of PTSD are far more personal.
Pace, who served as a flight nurse during the first Gulf War, witnessed the effects of PTSD firsthand in her close friend.
"She went through a hell of an ordeal," said Pace. "During the war she saw a lot of dead bodies that would come in.
"My friend had flashbacks and would wake up in the middle of the night sweating and crying. She was hospitalized and even attempted suicide."
The story of Pace's friend may be just one of a multitude of such cases, according to a new study in the current issue of the Archives of Internal Medicine.
Researchers looked at more than 100,000 troops returning from Iraq and Afghanistan treated at Veterans Affairs facilities between 2001 and 2005. They found that almost one-third suffered from a mental health problem.
The most common diagnosis was PTSD, which accounted for just over half of all the mental health cases found. But more than half of the veterans in the study had more than one mental health problem.
The large number of cases suggests an epidemic of mental health problems affecting those returning from the battlefield. And the authors say the government is not doing enough to treat these patients.
In the general population, an estimated 8 percent of Americans will experience PTSD at some point in their lives, with women twice as likely as men to develop the disorder. The incidence of the disorder increases to 30 percent for those who have spent time in war zones.
And the impacts of this condition can be grave; a survey, conducted last December, showed suicides among U.S. soldiers in Iraq doubled in 2005 over the previous year.
Twenty-two U.S. soldiers in Iraq took their own lives in 2005, a rate of 19.9 per 100,000 soldiers. In 2004, the rate was 10.5 per 100,000, and in 2003, the year the U.S.-led invasion of Iraq was launched, the figure was 18.8 per 100,000.
The survey also revealed that 13.6 percent of the soldiers reported symptoms of acute stress, and 16.5 percent reported a combination of depression, anxiety and acute stress.
The numbers reflect the sobering situation many soldiers face as they experience repeated tours of duty in the war-torn Middle East.
"What you have to remember is that those that are sent to Iraq are already screened for mental disorders ... so they are a healthy group," said Dr. Spencer Eth, medical director of behavioral health at St. Vincent Catholic Medical Centers in New York. "If they are healthy going in, why do they have such a great increase in suicide?"
Part of the stress may also be due to the uncertainty of troop deployments and redeployments.
"What is happening to some of the vets who we have seen here in clinic is that there is a lot of stress related to the unpredictability about when they are coming home or when they have to return," said Michael Petronko, director of the PTSD Program at the Graduate School of Applied and Professional Psychology at the State University of New Jersey, Rutgers.
"When you extend the tour, and it is extended two or three months, it's a catastrophic circumstance for them."