narcolepsy
"I fall between fatigue and narcolepsy. I've been this way for about 15 years. Thought I was just a sleepy person. Then my doctor suggested I might have sleep apnea. So I went to a sleep specialist and had the test. Mild results (6x an hour). She put me on a C-PAP machine and after a few months there was no improvement in my EDS. First there was Provigil which made me fall asleep a few hours after taking. Then on to Nuvigil which wasn't strong enough. Tried Ritalin next and the crash was too severe. At my suggestion the doctor prescribed dextroamphetamine salts and it has helped immensely. No more falling asleep at traffic lights, at the office or after work (no more strain on my marriage). I take 2x 30mg a day with zero side effects."