narcolepsy
"I was diagnosed with Sleep Apnea, for that I got a CPAP. But I also had trouble with zombie episodes and uncontrollable sleepiness  (at work, while driving, very scary). I was diagnosed with Narcolepsy several years ago (not formally tested though). I have all the symptoms (night terrors, sleep paralysis.), but I have not been tested for it. Anyway, my Sleep Doctor put me on it primarily because of several driving issues. It seems to work well, I have not dozed off or had a zombie episode since I have been on it. I still feel tired, and I can sleep if I want to, so I feel a little more in control. I also don't feel like a speed freak, like Adderal.  I am on 200 mg in the morning for the past 2 weeks. So far I am pleased with it."