RESUMEN
Many adults with ADHD respond to stimulant therapy, but controlled medication assessments have not been reported. We administered an effortful working memory task in four half-day sessions, double blind, at methylphenidate levels of 0, 5, 10 and 20 mg. Dose-response curves were established individually. Fifteen of 17 patients displayed a favorable response to one or more levels of medication; that is, they achieved more correct responses and less variability than on placebo. Each dose level elicited optimal performance from some of the patients. Unlike monitoring by self-report, the objective medication assessment offers an expeditious approximation to the ultimate optimal dose, potentially saving the patient weeks on an ineffective and/or excessive dosage regime.