PMDD or ADD?

I am on Zoloft right now. I was on Lexapro before but my insurance I have now doesn't cover it. When I firstbegan it I noticed a huge improvement in me after two weeks. I tried Prozac but didn't want to be on it because I have heard too many negative things about it. At least two others in my family are or were on Prozac and I feel as though it would have helped me if I had stayed on it. However I decided to go with zoloft. I feel like it helps a little bit sometimes but not enough. Is there a difference b/n ADD and PMDD? and if so which medication is best for each?