Adderall XR 20mg is a prescription medication primarily used to treat Attention Deficit Hyperactivity Disorder (ADHD) and narcolepsy. It is a long-acting formulation of the drug Adderall, which contains a combination of two stimulant medications: amphetamine and dextroamphetamine. These substances work by affecting the chemicals in the brain and nerves that contribute to hyperactivity and impulse control.