Adderall is a stimulant medication that's used to treat attention deficit-hyperactivity disorder (ADHD) and narcolepsy in adults and children. It contains the instant-release (IR) forms of dextroamphetamine and amphetamine salts. Adderall is available as a brand-name and lower-cost generic tablet that's taken by mouth. Your psychiatrist will adjust the dosage for you based on how well the medication works for you. Common side effects include trouble sleeping and loss of appetite.