narcolepsy
"I have been taking 10 mg 4 x daily for the last two years, and I have not fallen asleep while driving, standing still, taking finals (I am a 3rd year law student), or during class for all that time. This drug is good for me. The dose would be high for some, but I am around 200 lbs and 6' 3", so I need a moderately high dose based on body weight alone. I take the tablets, because they work quickly if I need them and I can skip doses that I do not need. Overall this drug has improved my quality of life vastly."