narcolepsy
"I had been on Adderall for a couple of years.  I was finally after being out of it most of the time during my life, was able to get things done and even if I did not get enough sleep at night (I still have that problem).  I was fine just taking 20mg in the morning and sometimes (rarely) 10mg around 11:00 am.  I did not gain nor loose weight.  I did have enough energy though to go to the gym and not worry about driving any time of the day.  All was good until Medicare said NO, I could not have it anymore.  I am now on Ritalin 30mg in the morning.  It helps a little but I don’t ever want to drive far, 5 miles is my limit, before I get sleepy.  My sleep is very restless and I wake up many times, avg. around 4hrs sleep out of 9hrs in bed."