Veterans' Cognitive Function, Mental Health, and Quality of Life After Hyperbaric Oxygen Therapy

This study is looking at whether hyperbaric oxygen therapy (HBOT) — breathing pure oxygen in a pressurized chamber — can improve memory, mental health, and quality of life in veterans living with mild traumatic brain injury (mTBI), PTSD, anxiety, or depression. **You may be eligible if...** - You are a veteran, age 18–75 - You have been diagnosed with mild traumatic brain injury, PTSD, anxiety, or depression - You have already tried at least one form of trauma-focused therapy (such as prolonged exposure, EMDR, or CBT) - Your psychiatric medications have been stable **You may NOT be eligible if...** - You have a lung condition such as COPD, emphysema, untreated pneumothorax, or a severe sinus or ear infection - You have an active cancer, active mania, psychosis, or serious suicidal thoughts - You have had previous HBOT treatment - You have diabetes requiring insulin, a blood disorder, or a seizure disorder - You are pregnant or use nicotine or illicit substances - You cannot speak English or attend scheduled visits Talk to your doctor to see if this trial is right for you.