Topiramate
"Awful.  I lost 10 pounds in 5 weeks before I had to quit Topamax due to side effects, which were terrible.  They included:  memory loss and "senior moments" which increased 10-fold, I think this medicine dropped my IQ at least 15 points, that "I'm not part of this world" feeling of disconnectedness; and overheating to the point that I simply could not work out.

Gained the 10 pounds back within 3 weeks of quitting."