Initial symptom severity of bipolar I disorder and the efficacy of olanzapine: a meta-analysis of individual participant data from five placebo-controlled studies

Background The efficacy of antipsychotics across the initial severity range in patients with acute mania remains unclear. Therefore, we examined the influence of baseline severity on the efficacy of olanzapine. Methods We did an individual participant data meta-analysis of double-blind, randomised controlled trials that compared olanzapine with placebo, identified through searches of the ClinicalStudyDataRequest.com database on Feb 2, 2016. We...