narcolepsy
"I'm still in the early stages of taking XYREM (week 6), but it has changed my life. I almost never take naps, and have had my narcoleptic episodes significantly reduced.  I get around 8 hours of sleep every night, and can stay awake with no issues all day. Sometimes in the morning I feel a little groggy, but can't get back to sleep which i'm sure is just the medicine wearing off as it goes away shortly after I get up and about."