Prescription stimulants are drugs that make you more alert and wakeful. They stimulate both the central nervous system and sympathetic nervous system and often produce euphoric feelings. Stimulants are used to treat narcolepsy and other sleep disorders and help patients with ADD or ADHD. The most used stimulants are Ritalin, Concerta, Adderall and Adderall XR although there are some improved drugs called eugeroics. Modafinil and adrafinil, marketed as Provigil and Olmifon belong to this class.