Sophia, My son is on Keppra, 2000 MG a day plus Zonegran and Lamictal. Keppra does cause irritability and hostility. But I think it lessens as time goes by but doesn't go away all together. His neurologist said Depakote was a good med but did cause weight gain in many people and a lot of weight gain so he never tried that one. I wish you luck with the Keppra. It is generally used as a med to control partial seizures if that helps to know.