I had some wicked side effects on Lamictal the first time I was on, when I went from 150mg to 200mg. I had cognitive difficulties and vertigo (yeah VErtigo).
It sucked. I could not walk down a flight of stairs! I quit taking it. Started on it again like 2 months ago, but was to stay at 150mg. I quit again though, it was making my skin all gross. Gee, do you think my doctor loves me or what...