Methylphenidate, sold under the brand name Ritalin and Concerta, among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It may be taken by mouth or applied to the skin, and different formulations have varying durations of effect. For ADHD, the effectiveness of methylphenidate is comparable to atomoxetine but modestly lower than amphetamine. Methylphenidate reduces core ADHD symptoms and may do so in part by enhancing cognitive control of behavior (i.e., working memory and inhibitory control).
At therapeutic doses, methylphenidate increases alertness and concentration and reduces hyperactivity and impulsive behavior in individuals with ADHD. Common side effects include loss of appetite, weight loss, trouble sleeping, and small increases in heart rate and blood pressure. Long-term treatment in children has been associated with slightly slower growth. Methylphenidate can be misused; dependence and withdrawal are mainly reported with high-dose or non-medical use and are uncommon at therapeutic doses.