The prescription drug Adderall is a mixture of amphetamine and dextroamphetamine. Narcolepsy and attention deficit hyperactivity disorder (ADHD) are the main conditions it is used to treat. Adderall reduces impulsivity, controls hyperactivity, and lengthens attention span in people with ADHD. Dopamine and norepinephrine, two brain chemicals involved in attention and impulse control, are the main ways it functions.