Hyperbaric Oxygen Therapy (HBOT) in Chronic Traumatic Brain Injury (TBI)/Post Concussion Syndrome (PCS) and TBI/Post-Traumatic Stress Disorder (PTSD)

Inclusion Criteria: * Adults, 18-65 years old * One or more mild-moderate TBI's characterized by loss of consciousness due to blast injury that is a minimum of one year old and occurred after 9/11/2001 * Absence of acute cardiac arrest or hemorrhagic shock at time of TBI. * Absence of intracranial neurosurgery post-TBI * Disability Rating Scale of 0-3 * Negative Michigan Alcohol Screening Test (MAST) * Negative Drug Abuse Screening Test (DAST) * Negative urine toxicology screen for drugs of abuse * Negative pregnancy test in females * Otherwise good health * Less than 90% on the Percent Back to Normal Rating Scale Exclusion Criteria: * Pulmonary disease that precludes HBOT * Unstable medical conditions that are contraindicated in HBOT * Severe confinement anxiety * Pregnancy * Other pre-TBI neurological diagnoses * Pre or post TBI history of substance abuse * Pre or post TBI history of alcoholism. * Participation in another experimental trial with active intervention. * High probability of inability to complete the experimental protocol. * Previous HBOT * History of hospitalization for past TBI, stroke, nonfebrile seizures, or any seizure history other than seizure at the time of TBI * Past or current history of mental retardation (baseline FSIQ \< 71. * Pre/post-TBI history of systemic illness with impact on CNS (P.I.'s decision)