RecruitingPhase 2Drug trialVeterans' Cognitive Function, Mental Health, and Quality of Life After Hyperbaric Oxygen TherapyThe purpose of this study is to evaluate how hyperbaric oxygen therapy (HBOT) may affect cognitive functioning, post-traumatic stress disorder (PTSD), depression, anxiety, and overall quality of life in veterans. 1. Does Hyperbaric Oxygen Therapy improve cognitive functioning, psychological well-being, and quality of life among veterans, as measured by pre-and post-treatment scores? 2. To what extent does Hyperbaric Oxygen Therapy improve cognitive functioning, psychological well-being, and qualify of life among veterans, after controlling for demographic characteristics.