Randomised study comparing the effects of the stimulant medications dexamphetamine and methylphenidate for treating attention deficit hyperactivity disorder (ADHD)

Dexamphetamine and methylphenidate are used in the treatment of attention deficit hyperactivity disorder (ADHD) but few studies directly compare their efficacy. This randomised study has been designed to compare the efficacy and side effects of dexamphetamine and methylphenidate during initial dose titration for treating ADHD. The dose titration schedule will be allocated by weight (maximum dose 1 tablet twice daily for children up to 25kg body weight, 1.5 tablets twice daily for those 25-35kg and 2 tablets twice daily for those weighing more than 35kg: tablets containing 5mg dexamphetamine or 10mg methylphenidate are conventionally considered equipotent). The dose will be increased weekly (as tolerated) over 4 weeks, aiming to establish the lowest dose that gives maximum improvement in functioning. A rating scale will be requested from the child's teacher describing the child's functioning before starting medication and on each dose. Side effects will be monitored with rating scale and measurement of weight and blood pressure. Cognitive functioning using a simple computer-based test will be assessed unmedicated and on each dose used during titration. After dose titration, routine clinic data on the participants will be collected (height, weight, side effects, medication, reasons for medication change) until the completion of 12 months on treatment.