Efforts by the Army to prevent and treat post-traumatic stress disorder seem to be working, new research suggests. A decade after the start of the wars in Afghanistan and Iraq, studies have shown that PTSD among troops is surprisingly low.

There is reason for cautious optimism when it comes to the prevalence of PTSD, researchers said. While early estimates suggested as many as 30 percent of troops might develop PTSD, current surveys show the actual rates are somewhere between 2.1 percent and 13.8 percent.

Researchers said this could be because the Army has implemented programs to not only prevent PTSD, but to treat it after the fact.

"As a society we're much more aware of these issues than ever before," study researcher Richard J. McNally, of Harvard University, said in a statement. "That is reflected by the fact that the military and the Veteran's Administration has established programs to ensure soldiers receive the best treatment possible. The title of my article is 'Are We Winning the War Against Post-Traumatic Stress Disorder?' I think a provisional answer to that is, 'Yes, we might be.'"

The study was published today, May 18, in the journal Science.

While part of the drop in PTSD rates may simply be that wars are less lethal — in a decade of war in Iraq, fewer than 5,000 American troops were killed, compared to more than 55,000 killed over a similar period in Vietnam — McNally suspect that new efforts by the Army to tackle the disorder sooner and ensure soldiers receive the best treatment available, may be helping, too.

"It's important to remember that simply being deployed carries a great deal of stress," McNally said. "Soldiers miss their family, and those who stay at home essentially become a one-parent family. Difficulties with children, or school or making ends meet — there are all kinds of stressors that have to do with separating families, let along having one member in a war zone. Fortunately, the military has taken steps to help soldiers cope with these stressors in addition to the traumatic combat stressors that can produce PTSD."

Several programs have also been instituted to help soldiers build the resilience necessary to reduce their risk for PTSD before being deployed, and to treat those at risk of developing the disorder after they return.

"It's not therapy per se, but a preventive intervention to help people put their experiences in perspective," McNally said. "It encourages soldiers to use the sort of emotional bonding that happens within units to reconnect with their families, and to see symptoms like hyper-vigilance not as symptoms of a mental disorder, but as something they need to adjust when they come home. It helps people realize that those things are part of the normal re-adjustment process."

And thus far, McNally said, the evidence suggests that the training has a positive effect.