Non-invasive Nerve Stimulation for PTSD and Sleep

This study is testing whether a non-invasive nerve stimulation device (applied to the skin, no needles or surgery) can help veterans who suffer from PTSD (post-traumatic stress disorder) and sleep problems, including those who also experienced a mild traumatic brain injury. **You may be eligible if...** - You are a veteran with a history of PTSD - You may also have a history of mild traumatic brain injury (such as a concussion) **You may NOT be eligible if...** - You have a serious psychiatric illness unrelated to PTSD or brain injury - You have other significant medical conditions that affect your thinking or cognition - You currently misuse prescription or illegal drugs - You require continuous oxygen for a breathing disorder Talk to your doctor to see if this trial is right for you.