OIF and OEF service men and women exposed to high levels of violence are at risk for developing mental health disorders including Post-traumatic Stress Disorder (PTSD) and Major Depressive Disorder (MDD). Even those with less severe symptoms who fail to meet diagnostic criteria for a mental health disorder may struggle to return to pre-deployment functioning. Studies suggest that a significant percentage of veterans may suffer from "subthreshold" PTSD; although their symptom presentation is less severe, these veterans experience emotional distress and reduced quality of life.