A preliminary controlled trial of divalproex in posttraumatic stress disorder.

Background: Case reports and open trials have reported beneficial effects of divalproex in the treatment of posttraumatic stress disorder (PTSD). The objective of this study was to conduct a placebo-controlled study of the efficacy and tolerability of divalproex in chronic PTSD patients.

Methods: Patients were randomized to receive placebo or divalproex. The primary outcome measure was the Clinician Administered PTSD Scale (CAPS).

Results: Of 29 patients randomized, 16 received divalproex and 13 placebo. There were no significant differences between groups in mean change from baseline to end point (last observation carried forward) on the CAPS total score or subscales except for a significant decrease in avoidance/numbing scores with placebo. The only significant difference in secondary outcomes was a greater improvement in Clinical Global Impression Scale-Severity favoring placebo.

Conclusions: Divalproex was not superior to placebo in this study. This could be due to lack of efficacy of divalproex in this population, inadequate sample size to detect differences, or other factors. Further study of divalproex is needed to better clarify the role of this agent in PTSD.