A note on the "paradoxical" effect of stimulants on hyperactivity with reference to the rate-dependency effect of drugs

The administration of stimulant drugs to hyperactive children often leads to a decrease in their excessive motor activity. This "paradoxical" effect is discussed in terms of the rate-dependency hypothesis which states that the effect of a given drug is determined by the baseline rate of behavior emitted by the subject. Amphetamines decrease response output under schedules maintaining high response rates, but increase response output under schedules maintaining low response rates. In hyperactive children, when baseline motor activity is high, the stimulant drug should, therefore, produce a reduction in such behavior. We also suggest that greater emphasis be placed on reporting individual data and that more detailed specification be made of the target responses.