I'm not suffering with bipolar disorder, but did try Topamax.

I gained weight unbelieveably and that was over a year ago and I still can't lose it. I wasn't on the drug long, as it was nasty. I won't go into all the details, but it did give me a gross sense of smell and taste of things. (And I lost my sense of taste and smell in the accident.) It nearly killed me, this drug.