Transcutaneous Vagal Nerve Stimulation in Veterans With Posttraumatic Stress Disorder

This study is testing whether a small device worn behind the ear that gently stimulates a nerve (transcutaneous vagal nerve stimulation, or tVNS) can reduce PTSD symptoms in veterans without using medication. **You may be eligible if...** - You are a veteran between 18 and 75 years old - You have been diagnosed with PTSD (based on DSM-5 criteria) **You may NOT be eligible if...** - You have a history of mild, moderate, or severe traumatic brain injury (TBI) - You are pregnant - You have a history of meningitis or other neurological conditions - You have a current alcohol or substance use disorder (within the past 12 months) - You have a history of schizophrenia, bipolar disorder, or an eating disorder - You have active suicidal thoughts with a plan - You are currently taking opiates or benzodiazepines (like Valium) - You have a serious heart, liver, kidney, or neurological illness Talk to your doctor to see if this trial is right for you.