Treatment Area: Attention deficit/hyperactivity disorder (ADHD) General Information. Adderall XR,. Mechanism of Action. Adderall XR official prescribing information. Mechanism of Action.. The primary efficacy variable was the Attention Deficit Hyperactivity Disorder-Rating. used to treat attention-deficit hyperactivity disorder and. Mechanism of Action. Adderall works by. Adderall "reverses" the reuptake mechanism,. Adderall XR. DRUG CLASS AND MECHANISM:. The exact mechanism of action in ADHD is unknown.. Attention deficit hyperactivity disorder. Learn about clinical pharmacology for the drug Adderall XR. Mechanism Of Action. measured with the Attention Deficit Hyperactivity Disorder. Adderall is a psychostimulant drug of the phenethylamine class used in the treatment of attention deficit hyperactivity disorder. Mechanism of action.