narcolepsy
"I can't stay awake without it. I was taking 36mg of Concerta at 6am, another 36 at 8am, and then falling asleep at my desk at 9. Now I still take the 6am dose, but I take the Methylin at 8 and then at 10 if I need it. I was falling asleep every day. Now I can actually stay awake! No other medicines have worked for me, and I have certainly tried a lot."