DRUG CLASS AND MECHANISM: Adderall contains amphetamine salts (amphetamine and dextroamphetamine) and is used for treating attention-deficit hyperactivity disorder (ADHD) and narcolepsy. Amphetamines stimulate the brain by increasing the level of neurotransmitters, dopamine and norepinephrine, in the brain. (Neurotransmitters are chemicals produced by nerves that are released and attach to other nearby nerves as a means of communication among nerves.) The exact mechanism of action in ADHD is unknown. Adderall XR is an extended release form of Adderall. Adderall was approved by the FDA in 1996.