Of 292 patients (210 males and 82 females) receiving medication for attentiondeficit hyperactivity disorder (ADHD), 272 (93%) responded well to sustained-release dextroamphetamine (D-Amp) and 21 patients (7%) to sustained-release methylphenidate (MPD). The dose of D-Amp ranged from 0.2 to 3.6 mg/kg/day and the dose of MPD from 1.4 to 7.7 mg/kg/day, without side effects requiring cessation of therapy. This suggests that the clinical improvement rate can be increased to nearly 100% in appropriate situations