narcolepsy
"My doctor seems to only identify with how it effects him, which he sometimes takes when going on a long trip.  He says, It lasts for 8 to 12 hours.  No on me 3 to 4 hours.  I looked up what other narcoleptics said.  They said they take 250 mg twice a day.  That would be good, but who can afford it.  My part is $300 for once a day.  I have not experienced any side effects that I am aware of, but I am taking the next four days without any nuvigil to see if my sleep wake pattern gets better.  My present problem may or may not be related to nuvil.  I don't know.  I wake up in the middle of the night wide awake.  Sometime I can go back to sleep after 3 or 4 hours, but sometimes I never do.  So, I am functioning, poorly, on about 4 hours of sleep"