obstructive sleep apnea/hypopnea syndrome
"I have  taken this medicine for sleep apnea and ADD as a replacement for Ritalin, which I became addicted to for a few years.  Provigil does not affect me the same way in terms of a desire to increase the dose and it is very effective for day time wakefulness and for keeping my focus.  I have had no negative effects from this - only positive.  It is very expensive and if it wasn't for insurance coverage the medicine would cost $1,500 per month if out of pocket.  "