I used to get bad headaches (migraines I know now) when I was on depakote. My pdoc didn't think they were related b/c depakote treats migraines (I think I remember this right although nobody has ever offered me depakote for migraines and that's weird) but I would get them when my level was too high. Which happened easily b/c I had difficulty maintaining a high enough level and then would drift into "too high" and back a lot.