There is little to no evidence from controlled trials to suggest that topiramate is effective in the treatment of patients with bipolar disorder. One small randomized study in patients with bipolar depression suggested that the drug reduces depressive symptoms (McIntyre et al. 2002). An additional open-label trial also suggested that topiramate had antimanic activity. However, the sponsor – Janssen – has conducted, but not published, at least four double-blinded, placebo-controlled trials in the treatment of mania which were negative and has announced that it is discontinuing development in this area.