Efficacy of divalproex sodium in patients with panic disorder and mood instability who have not responded to conventional therapy.

OBJECTIVE

To determine the efficacy of divalproex sodium in the treatment of psychiatric outpatients with treatment refractory panic disorder and comorbid mood instability.

METHOD: This was an 8-week, open-trial, flexible-dose outcome study conducted at a tertiary care referral centre. Individuals with panic disorder who failed to respond to a cognitive behavioural treatment program and standard antipanic medication, who also suffered from mood instability, were chosen to participate in the study. Divalproex sodium was administered at a flexible dose to reach serum levels of 300 to 600 mumol/L (45 to 90 ug/ml) unless limited by tolerance. Patients were rated by self- and rater-administered questionnaires that measured the number of panic attacks, the degree of agoraphobic avoidance, the levels of depression, anxiety, and mood swings, and the perceived sense of well being.

RESULTS

Thirteen subjects were enrolled in the study, and 10 subjects completed it. Two dropped out early because of the medication's side effects, and 1 was lost within the first month of follow-up. All 10 subjects showed significant improvement in depressive and anxiety symptoms and mood instability. There was also a statistically and clinically significant improvement in panic attacks and measures of quality of life.

CONCLUSIONS

These findings suggest that divalproex sodium is useful in the treatment of patients with panic disorder and concomitant mood instability, who are refractory to conventional treatment. Double-blind trials will be required to verify these findings.