The combination of dextroamphetamine and amphetamine (Adderall, Adderall XR, Mydayis) is used as part of a treatment program to control symptoms of attention deficit hyperactivity disorder (ADHD; more difficulty focusing, controlling actions, and remaining still or quiet than other people who are the same age). Adderall is used to treat ADHD in adults and children 3 years of age and older. Adderall XR is used to treat ADHD in adults and children 6 years of age and older. Mydayis is used to treat ADHD in adults and children 13 years of age and older. Dextroamphetamine and amphetamine (Adderall) is also used to treat narcolepsy (a sleep disorder that causes excessive daytime sleepiness and sudden attacks of sleep) in adults and children 12 years of age and older. The combination of dextroamphetamine and amphetamine is in a class of medications called central nervous system stimulants. It works by changing the amounts of certain natural substances in the brain.