hypersomnia
"I have used Provigil for about 6 years for daytime sleepiness/fatigue. About 2 weeks ago I began taking Nuvigil instead. The effect is definitely longer-lasting by several hours, and initially it seemed more potent yet "cleaner" in terms of side effects than Provigil. However, more recently when I've taken it after a night of poor sleep I've had to increase the dose and I get a lot of tension headaches, as with Provigil. 150 mg lasted all day at first, now I've had to take a little more. Still, I'd rate it an improvement over Provigil - how much so, time will tell."