narcolepsy
"I have taken this medication for over 5 years to help me stay awake due to a narcolepsy diagnosis.  The drug is very effective and I have not become addicted in anyway although I have developed a tolerance to the medication and have had to increase my dosage to now the highest amount available and now will most likely have to change to another medication.  The side effects have also increased including mood swings and and feelings of depression when the drug wears off and now I am convinced that it is time to switch medications.  Even with these increased side effects, without this drug I wouldn't have been able to function as a normal human being and I am now nervous that I won't be able to find another medication that was this effective."