There are two meds that have made a real difference with my moods. One was Risperdal, which I felt the effects of over the course of a few weeks. The other was Wellbutrin which I felt the effects of within a few days. There was also Depakote, and although it helped tremendously, I didn't feel the full effect until I added the other meds. I also take Prozac, Propanolol, and Trazodone.

I agree with Ygrec. I think it is based on the dosage, your metabolism, and who knows what other reactions inside your brain, and the fact that everyone is so very different.