This study is evaluating the efficacy of virtual reality exposure therapy (VRET) by comparing it to prolonged exposure therapy (PE) and a waitlist(WL) group for the treatment of post traumatic stress disorder (PTSD) in active duty (AD) Soldiers with combat-related trauma. The investigators will test the general hypothesis that 10 sessions of VRET or PE will successfully treat PTSD, therapeutically affect levels of physiological arousal, and significantly reduce perceptions of stigma toward seeking behavioral health services.