Placebo effect in randomized, controlled studies of acute bipolar mania and depression.

Randomized, double-blind, placebo-controlled, parallel group clinical trials have been the standard methodology for establishing the efficacy of new treatments for patients with bipolar disorder in manic, mixed, or depressive episodes. We examine the placebo response rate in acute treatment trials of acute mania (and mixed states) and bipolar depression. Also addressed are potential variables associated with placebo response, strategies to minimize placebo response, the optimum duration of placebo-controlled acute treatment trials, possible alternatives to the use of placebo, and the ramifications of these issues with regard to the design of studies in children, adolescents, and older adults with bipolar disorder.