Effect Size of Lithium, Divalproex Sodium, and Carbamazepine in Children and Adolescents With Bipolar Disorder

To develop effect sizes for 3 mood stabilizers-lithium, divalproex 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. Forty-two outpatients with a mean age of 11.4 years (20 with bipolar I disorder and 22 with bipolar II disorder) were randomly assigned to 6 weeks of open treatment with either lithium, divalproex sodium, or carbamazepine. The primary efficacy measures were the weekly Clinical Global Impression Improvement scores and the Young Mania Rating Scale (Y-MRS). Using a ≥50% change from baseline to exit in the Y-MRS scores to define response, the effect size was 1.63 for divalproex 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 as follows: sodium divalproex, 53%; lithium, 38%; and carbamazepine, 38% (χ22 = 0.85, p = .60). All 3 mood stabilizers were well tolerated, and no serious adverse effects were seen. Divalproex sodium, lithium, and carbamazepine all showed a large effect size in the open treatment of children and adolescents with bipolar I or II disorder in a mixed or manic episode.