Enhancing Extinction Learning in Post Traumatic Stress Disorder (PTSD)

Posttraumatic stress disorder (PTSD) is a condition that involves intense memories of a traumatic event and intense, persistent feelings of anxiety. There are several effective therapies for PTSD, but they are often time consuming. The investigators want to see if the investigators can shorten treatment time while keeping therapy effective by adding a medication called methylene blue, USP, taken orally as a pill, to the therapy. The specific aims are: 1) To see whether medication plus psychotherapy improves PTSD symptoms more than placebo plus psychotherapy or a waitlist; 2) To examine the long-term outcome of those receiving medication plus psychotherapy 1 and 3 months after treatment has ended; 3) To examine whether medication plus psychotherapy helps with depression, trauma-related cognitions, and functioning.