There is an urgent need to improve the treatment of veterans diagnosed with PTSD. The National Vietnam Veterans Readjustment Study (NVVRS) revealed that more than 15% of veterans met diagnostic criteria for PTSD 20 years after the end of this war. Each U.S. military engagement and peacekeeping mission since the Vietnam War has added to the number of veterans diagnosed with PTSD. The only FDA approved drug treatments for PTSD have limited efficacy for men with military service related PTSD. The purpose of this study is to determine if Risperidone is effective in treating military service related PTSD.

Primary Hypothesis: Risperidone will reduce symptoms of PTSD, relative to placebo, in veterans with military service related chronic PTSD who have been partial or non-responders to antidepressant medications.

Secondary Hypothesis: Risperidone is safe and well-tolerated in veterans with military service related chronic PTSD, and patients will comply with its prescription. As a result, patients will show improvement in the secondary consequences of PTSD for the veteran and for the VA.

Intervention: Usual (PTSD) care plus Risperidone vs usual (PTSD) care plus placebo

Study Abstract: Four hundred veterans with the diagnosis of military-related PTSD will be enrolled at 20 VAMC hospitals over a two-year period. An equipoise stratification design will be used to randomize patients in a double-blind manner to risperidone or placebo (~200 patients in each group) for six months of treatment. Usual care will be provided for all patients for treatment of PTSD and other psychiatric and medical disorders. Comparisons between the risperidone and placebo groups will be made at the end of six months to answer the primary question. The sample size is calculated to give 90% power at the two-sided alpha level of 0.05 for the overall test for the CAPS score change.

STUDY UPDATE/NOTES: Study kick-off is being planned for spring 2005.

Ages Eligible for Study:  18 Years and above,  Genders Eligible for Study:  Both

Criteria

• Veterans, 18 years and older,
• Diagnosed with military service related PTSD, who are being seen at an outpatient VA PTSD Clinic and
• Have a history of partial or non-response to two or more antidepressants.