Effect size of lithium, divalproex sodium, and carbamazepine in children and adolescents with bipolar disorder

Objective: To develop effect sizes for 3 mood stabilizers-lithium. divalpro ex sodium, and carbamazepine-for the acute-phase treatment of bipolar I or II disorder, mixed or manic episode, in children and adolescents aged 8 to 18 years. Method: Forty-two outpatients with a mean age of 11.4 years (20 w ith bipolar I disorder and 22 with bipolar II disorder) were randomly assig ned to 6 weeks of open treatment with either lithium, divalproex sodium, or carbamazepine. The primary efficacy measures were the weekly Clinical Glob al Impression Improvement scores and the Young Mania Rating Scale (Y-MRS). Results: Using a greater than or equal to 50% change from baseline to exit in the Y-MRS scores to define response, the effect size was 1.63 for divalp roex sodium, 1.06 for lithium, and 1.00 for carbamazepine. Using this same response measure with the intent-to-treat sample, the response rates were a s follows: sodium divalproex, 53%; lithium, 38%; and carbamazepine, 38% (ch i(2)(2) = 0.85, p = .60). All 3 mood stabilizers were well tolerated. and n o serious adverse effects were seen. Conclusions: Divalproex sodium, lithiu m, and carbamazepine all showed a large effect size in the open treatment o f children and adolescents with bipolar I or II disorder in a mixed or mani c episode.