My doctor put me on 20mg generic ritalin one in the am and one in the pm. Totaling 40mg. I started takeing both in the am and it worked much better. I asked him if I could go to 40mg am and 40mg pm since it only seems to last 5 hours for me. He said I could take one am one noon and one afternoon or two in am and one in afternoon totaling 60mg. I am confused and frustrated because if 40mg works for me and it is gone after 5 hours than why can't I keep a consistent 40 throughout the day. The way he wants it puts me on a roller coaster up down. Any thoughts?