Divalproex extended-release in acute bipolar II depression

Divalproex extended-release (divalproex-ER) is effective in acute mania, and limited data suggest divalproex may have efficacy in acute bipolar depression.

A 7-week, open-label trial of divalproex-ER monotherapy or adjunctive therapy was conducted in 28 outpatients (15 female, mean age 36.7+/-9.1, and mean duration of illness 22.1+/-11.1 years) with bipolar II depression (39% with rapid cycling course of illness within the prior year). Divalproex-ER was generally given as a single dose at bedtime, starting at 250mg and increased by 250mg every 4 days to symptom relief or adverse effects. Efficacy was assessed using weekly prospective Montgomery Asberg Depression Rating Scale (MADRS) scores.

Overall, mean divalproex-ER final doses and serum concentrations were 1469mg/day and 80.1microg/mL, respectively. Mean MADRS scores (last observation carried forward) decreased significantly from baseline in patients in the overall group (from 30.1 to 15.2, p<.00001). The overall response rate was 54%. Divalproex-ER therapy was generally well tolerated, with no early discontinuations due to adverse events.

This study is limited by a small sample size and an open-label study design with no placebo control.

Divalproex-ER as monotherapy and adjunctive therapy was well tolerated and yielded an overall response rate of 54% in bipolar II depression. Based on the results of this pilot study, randomized, double-blind, placebo-controlled studies of divalproex-ER in bipolar II depression are warranted.