Ritalin—a brand name for the central nervous system (CNS) stimulant medication methylphenidate—is prescribed by medical professionals to treat ADHD and narcolepsy. Ritalin is available in immediate-release and sustained-release (Ritalin SR) formulations that are orally ingested as tablets. Due to its potential for misuse, Ritalin is listed as a Schedule II substance under the Controlled Substances Act (CSA)