The time course effects of four doses of Adderall® (5, 10, 15, and 20 mg) were compared to placebo and a single dose of methylphenidate in a randomized, double-blind, crossover study of 30 children with attention deficit hyperactivity disorder (ADHD) treated at the Child Development Center, University of California, Irvine. A capsule was given AM and time-response and dose-response were assessed every 1.5 hours through the day, using subjective teacher ratings of attention, and objective math test scores at each classroom session. Significant effects were observed by 1.5 hours with doses of Adderal above 5 mg, and time of peak effects and duration of action increased with the dose. From 5 to 20 mg, the duration of action ranged from 3.5 hrs to 6.4 hrs. Side effects showing a dose-related increase after Adderal adminstration included picking at skin or fingers, appetite loss, and trouble sleeping. Dosage was adjusted in 5 subjects, and 2 elected to withdraw from the trial, one with anorexia (20 mg dose) and one with anorexia, “tearful, sad, depressed“ and “dull, tired, listless“ complaints (10 mg dose). Adderal is recommended in treatment of ADHD.