 In this study, the investigators will be looking at the behavioral and neurological changes changes in the brain and the reductions in PTSD symptoms that may come from participating in this treatment. The investigators are interested in determining if treatment does reverse changes in the brain caused by PTSD and mTBI. To help the investigators understand changes in how the brain functions, the participants will complete a functional magnetic resonance imaging fMRI scan before and after either a 8-week course of IRV or 8 weeks of education about PTSD and mTBI. Participation will help the investigators understand how therapy for PTSD and mTBI impacts the brains response to emotions and therapeutic processes. 