Background: To determine the efficacy of divalproex sodium in the treatment of panic disorder, divalproex sodium was administered in a 6-week open clinical trial to 12 patients who had a primary DSM-III-R diagnosis of panic disorder.
Method: Treatment was begun at 500 mg of divalproex sodium daily and was increased according to clinical response and side effects. Clinicians completed a Clinical Global Impressions Scale weekly and a Hamilton Rating Scale for Anxiety every other week. Patients completed a panic-attack diary and a Brief Symptom Inventory weekly.
Results: All 12 patients completed the study, and all were moderately to markedly improved. Measures of panic attacks and anxiety improved more quickly and robustly than measures of phobic avoidance. Eleven of the 12 patients elected to remain in treatment and at 6-month follow-up had sustained improvement.
Conclusion: These findings suggest that valproic acid may be effective for the treatment of panic disorder. Double-blind studies will be required to further verify these findings.