Response to placebo among bipolar I disorder patients experiencing their first manic episode

Background: The first episode of an illness may respond differently to any treatment compared to multiple episodes of the same illness. This study det ails the treatment response of six first-episode manic patients who partici pated in a previously reported study of 139 subjects comparing olanzapine t o placebo in bipolar I mania (Tohen M, Sanger TM, McElroy SL, Tollefson GD, Chengappa KNR, Daniel De. Olanzapine versus placebo in the treatment of ac ute mania. Am J Psychiatry 1999; 156: 702-709) Methods: Six first-episode subjects participated in a 3-week double-blind, random assignment, parallel group, placebo-controlled study of olanzapine f or bipolar mania. The Young Mania Rating Scale (Y-MRS). Clinical Global imp ression, and Hamilton Depression ratings were administered weekly. Lorazepa m as rescue medication was permitted for the first 10 days. Results: Five subjects were randomized to placebo and one to olanzapine. Tw o subjects (40%) with psychotic mania (who also had their first-illness epi sode) were assigned to placebo and responded with greater than 50% reductio n in the Y-MRS score and also remitted in 3 weeks. Another placebo-assigned subject had a 46% reduction in the Y-MRS scores, and two placebo-assigned subjects worsened. The olanzapine-assigned subject had a 44% reduction in t he Y-MRS score, In contrast, 34 of 69 (48.6%) multiple-episode olanzapine s ubjects responded and 14 of 61 (23.0%) of placebo-treated subjects did. Conclusions: This preliminary data set suggest there may be differences in treatment response between first-illness episode versus multi-episode bipol ar manic subjects. Larger numbers of subjects with these illness characteri stics are needed to either confirm or refute this suggestion.