Methylphenidate for Attention Deficit Hyperactivity Disorder and Autism in Children

Methylphenidate-extended release was taken in the morning of the MPH treatment trial. Each participant underwent 1 week of the each of the doses as determined by body weight. The lower body weight group (20 to 24 kg/44 to 52.8 lbs) took 10 mg Ritalin LA to 20 mg. The medium body weight group (25 to 33 kg/55 to 72.6 lbs) took from 10 mg Ritalin LA to 30 mg. The higher body weight group (34 to 59 kg/74.8 to 129.8 lbs) took 20 mg Ritalin LA to 40 mg.

Methylphenidate-immediate release was taken in the late afternoon. Each participant underwent 1 week at each of the 3 dose levels as determined by body weight. The lower body weight group (20 to 24 kg/44 to 52.8 lbs) took 2.5 mg IR-MPH and 2 weeks of 5 mg. The medium body weight group (25 to 33 kg/55 to 72.6 lbs) took 2 weeks of 5 mg IR-MPH and 1 week of 10 mg. The higher body weight group (34 to 59 kg/74.8 to 129.8 lbs) took 1 week of 5 mg IR-MPH and 2 weeks of 10 mg.

Participants will take a placebo for 1 full week of the randomized drug trial. They will take one capsule in the morning and one capsule in the afternoon.