Amphetamine is a prescription CNS stimulant commonly used to treat attention-deficit disorder (ADD) and attention-deficit hyperactivity disorder (ADHD) in adults and children. It is also used to treat symptoms of traumatic brain injury and the daytime drowsiness symptoms of narcolepsy and chronic fatigue syndrome. Initially it was more popularly used to diminish the appetite and to control weight. Brand names of the drugs that contain amphetamine include Adderall and Dexedrine. The drug is also used illegally as a recreational club drug and as a performance enhancer. The name amphetamine is derived from its chemical name: alpha-methylphenethylamine. The name is also used to refer to the class of compounds derived from amphetamine, often referred to as the substituted amphetamines.