A Placebo-Controlled Trail 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.