narcolepsy
"I was ready for the nut house, when finally diagnosed with narcolepsy.  I would need to take a 10-15 min nap every 45 min.  I would start feeling like throwing up and fainting.  I had losed my ability to function, think or anything else. I could not drive, as I would nod out constantly, within the first mile.  I could not even do basic thought process like addition/subtraction in my head.  After the first dose, I felt immediately better.  I could make it thru a normal day, without falling asleep.  Even better, my thought process came back.  I could figure things out, understand things.  and I could drive without nodding out.  I have been on this for a year. same dosage, I stop for a day or two every 3 mths. as instructions say."