New research says that the rate of troops who fought in Iraq returning to the U.S. with post-traumatic stress disorder (PTSD) may be as high as 35 percent.

The estimate comes from a feature in the current issue of Management Science. It is based on data collected from military surveys. To reach the figure of 35 percent, the research authors Michael Atkinson and Adam Guetz combined mathematical models with data relating to the rate of deployments and PTSD rates already on record.

Although current data suggest only half that many soldiers are returning with PTSD, the authors factored in future deployments and the lag time between events that cause PTSD and the onset of symptoms.

The research concludes that the Department of Veteran Affairs should prepare for this high number of returning soldiers with PTSD by increasing mental health support for returning military personnel.

Fort Bragg has begun a program that used meditation, yoga, and group therapy to alleviate PTSD symptoms. Those who suffer from stress may also take ginseng or B vitamin supplements, which may help reduce the severity of their anxiety.