Posttraumatic stress disorder (PTSD) is a chronic, debilitating condition that affects our nation's Veterans at staggering rates. The purpose of this study is to examine the ability of a medication (oxytocin) to enhance Prolonged Exposure (PE) therapy for Veterans with Posttraumatic Stress Disorder (PTSD). PE is a widely used cognitive behavioral intervention (talk therapy) for Posttraumatic Stress Disorder (PTSD). In order to accomplish this goal, we are recruiting participants for a clinical trial. Participants enrolled in this trial will complete 10 weeks of a treatment phase, that includes weekly doses of either the investigational study medication or an inactive placebo. In addition, all participants will receive 10 weekly sessions of PE talk therapy. Once per week before each therapy session, participants will take a dose of medication intranasally. This study has the potential to improve patient care practices, advance the science in this area, and decrease public health costs.

The purpose of this study is to determine whether a new medical technology can help reduce post-operative total knee or hip pain when combined with a Cognitive-Behavioral intervention (CBI).

This new medical technology, is called transcranial direct current stimulation (tDCS), it uses a very small amount of electricity to temporarily stimulate specific areas of the brain thought to be involved in pain reduction. The electrical current passes through the skin, scalp, hair, and skull and requires no additional medication, sedation, or needles.

This study will investigate the effects of tDCS, the Cognitive-Behavioral (CB) intervention and their combination on pain among veterans following total knee arthroplasty (TKA) or total hip arthroplasty (THA). You may benefit in the form of decreased pain and opioid requirements following your knee or hip replacement surgery. However, benefit is only likely if you are randomized to one of the 3 (out of 4) groups.

This study hopes to determine the effects of these interventions and their combined effect on post-operative pain, opioid use and functioning during the 48-hour post-operative period following a total knee or hip replacement.

The purpose of the study is to generate a bio bank of specimens for research. We will tissue that would otherwise be discarded from clinical or surgical procedure and information from medical records. We will also collect discarded blood, urines and sputum. Collecting samples will help to better understanding the mechanisms of cardiovascular diseases, identify biomarkers for early diagnosis and to predict safety and efficacy of new therapies.

Individuals are being asked to volunteer for a research study. Research studies are voluntary and include only those who choose to take part. The purpose of this research study is to compile a repository of participants who are willing to participate in rehabilitation research studies.

Participants will complete a datasheet that includes contact information and basic medical conditions. Once the datasheet is complete, participants will then await contact from VA Investigators. The study will continue until the participant decides they no longer wish to participate or becomes deceased.

There will be no direct benefit to participants from taking part in this study. The risk associated with this study is a potential loss of confidentiality.