narcolepsy
"Nuvigil worked great at 150 mg for a few months, then I needed to supplement with a quart of coffee in the mornings to keep me going until 1 pm.  Bumped up to 225 mg.  Not much better.  Very expensive, $90 per month ($3 per pill).  Aggressiveness, headaches, and thirst until I got used to it.  No side effects now."