Adderall XR 15mg is a central nervous system stimulant prescription medicine. It is used for the treatment of attention-deficit hyperactivity disorder (ADHD). Adderall may help increase attention and decrease impulsiveness and hyperactivity in patients with ADHD. Adderall should be used as a part of a total treatment program for ADHD that may include counseling or other therapies. Adderall is also used in the treatment of a sleep disorder called narcolepsy.