A Placebo-Controlled Trial of D-Cycloserine and Exposure Therapy for Combat-PTSD

War-zone-related posttraumatic stress disorder (PTSD) is a major psychiatric disorder that includes specific disabling symptoms and impairments that interfere with a soldier's ability to do his or her job. There is strong evidence for cognitive behavior therapy (CBT) in treating PTSD in civilians, which suggests a prescription for returning veterans, but approximately 40% of patients retain a PTSD diagnosis (e.g., Foa et al., 1999) and drop-out rates are \~25%. It is imperative to develop novel evidence-based early interventions that are more acceptable to recent veterans and less draining of treatment resources. If CBT can be shortened and its efficacy boosted by cognitive enhancers then it is more likely that soldiers will get the most efficacious treatments for acute stress and PTSD. Our aim is to develop a program that is brief and effective, but will have long-term benefits for veterans by virtue of its greater amenability to self-management and treatment adherence beyond the therapy context. This study is a randomized, controlled, double-blind treatment trial comparing CBT plus DCS to CBT plus placebo. Participants will be 68 OEF/OIF veterans with PTSD randomly assigned to CBT plus DCS or CBT plus placebo. Procedures to screen subjects prior to randomization include a detailed phone screen, administration and collection of questionnaires, a medical assessment, and two baseline structured clinical interviews. Following randomization, both groups will receive the identical 6 session exposure-based CBT protocol. The DCS-augmented group will receive 50 mg of DCS 30 minutes prior to the four CBT sessions involving imaginal exposure, whereas the placebo-augmented group will receive a placebo pill prior to these sessions. Assessment interviews conducted by independent evaluators will occur at pre-treatment, post-treatment, and at 3, and 6-month follow-up. Self-report measures will also be administered at screening, throughout the 6 weeks of treatment, and at 3- and 6- month follow up. Comparison(s): OEF/OIF veterans with PTSD treated with CBT plus DCS, compared to OEF/OIF veterans with PTSD treated with CBT plus placebo.