It’s Official: Topamax doesn’t work for Bipolar Disorder

It’s been a bad, bad year for Topamax (topiramate). First, the results of four controlled trials of Topamax as monotherapy for mania showed that it outperforms placebo in only two ways: more paresthesia and more weight loss (Kushner et al, Bipolar Disorders 2006;8:15-27). The latest blow concerns a very common intervention in psychiatry: the addition of Topamax to lithium or Depakote as a way of augmenting their anti-manic actions. Who hasn’t tried this? Researchers randomly assigned 287 manic or mixed manic patients to either adjunctive Topamax (average dose 255 mg/day) or adjunctive placebo. After 12 weeks, there were no treatment differences in either the primary or secondary measures, though Topamax produced about 5 lbs. more weight loss than placebo (Chengappa et al, J Clin Psychiatry 2006;67(11):1698-1706).