Time-response analysis of the effect of stimulant medication on the learning ability of children referred for hyperactivity.

This report introduces a method for obtaining behavioral time-response information for a short-acting psychotropic drug (methylphenidate [Ritalin]) that is widely used to treat behaviorally hyperactive children. We used a laboratory learning task to document that between one and two hours after the administration of a single dose of methylphenidate, the drug exerts its maximum effect on performance in a learning task in the laboratory. This effect on cognitive performance dissipates within the same day. This rapid and transient effect of methylphenidate makes it possible to classify patients in a single day into those who respond favorably and those who respond adversely to the drug in terms of its effect on cognitive behavior.