Comparison of Two Anticonvulsants in a Randomized, Single-Blind Treatment of Hypomanic Symptoms in Patients with Bipolar Disorder

Abstract

Oxcarbazepine was compared to divalproex to assess clinical effectiveness of a proven agent, divalproex, against a newer, less studied agent, oxcarbazepine, in the treatment of hypomania. Thirty patients with bipolar disorder, currently hypomanic, were randomized to receive oxcarbazepine or divalproex as add-on or monotherapy for 8 weeks. A rater blind to treatment assignment performed all symptom ratings. Hypomania and depression were rated using the Young Mania Rating Scale (YMRS) and the Inventory of Depressive Symptoms-Clinician Version (IDS-C). Random regression models were used to assess clinical symptom scores. There were no significant differences of YMRS or IDS-C scores between groups. Mean YMRS scores at baseline were 22.07+/-5.86 and 20.53+/-6.02 for the oxcarbazepine and the divalproex groups, respectively. Mean percent reduction from baseline to week 8 for the YMRS was 63.8% and 79.0% for oxcarbazepine and divalproex groups, respectively. Mean percent reduction from baseline to week 8 for the IDS-C was 48.7% versus 19.7% for oxcarbazepine and divalproex groups, respectively. Significant antimanic efficacy was noted for each medication. Both medications were generally well tolerated. In this pilot study, oxcarbazepine was as effective as divalproex in the treatment of hypomania. Further controlled trials are warranted.