narcolepsy
"Hi, I have taken this medicine for a year. I have found that it works, but it takes a lot of work (if that makes any sense.) I
I am on 400mg a day for narcolepsy. I have found with this medicine if I take it and then eat, almost no effect, if I eat wait about an hour, take the pill then that's fine. 
If I don't drink a lot of water then it doesn't matter, because it doesn't work. 
For a person that always wants to sleep, scheduling this little pill twice a day is almost not worth it."