narcolepsy
"Ritalin LA: I have taken this (10mg) along with "normal" release methylphenidate/Ritalin to treat narcolepsy for about 4 years.  The LA does not give me the jittery feeling of the short acting Ritalin.  I only supplement the LA with the short acting because the LA keeps me awake (or at least doesn't offer restful sleep) for about 8 hours, while the short acting version lasts about 4 hours.  Without these medications, particularly Ritalin LA, I would not be able to maintain any job that requires its employees to stay awake...which is pretty much all of them!  The only downside is the excessive cost.  Without insurance, about 10% of my gross salary would go to pay for this ONE prescription."