Enhancing Week-long Psychological Treatment for PTSD With Ketamine

This study is testing whether adding a low dose of ketamine (an anesthetic sometimes used for depression) to an intensive one-week therapy program can improve outcomes for people with severe, long-lasting PTSD. **You may be eligible if...** - You are between 21 and 70 years old - You have been diagnosed with chronic PTSD (symptoms lasting more than 1 year) rated as severe on a standard clinical scale - You are able to read and write in English - If you take antidepressants or certain other psychiatric medications, you have been on a stable dose for at least 4 weeks - If female, you are not pregnant and are using an acceptable form of birth control (or are post-menopausal or surgically sterile) **You may NOT be eligible if...** - You have a diagnosis of borderline personality disorder, OCD, schizophrenia, or schizoaffective disorder - You currently have serious, active suicidal thoughts - You have a history of certain heart conditions, uncontrolled blood pressure, or significant substance use that would make ketamine unsafe - You had a manic episode in the 30 days before enrolling Talk to your doctor to see if this trial is right for you.