ABSTRACT
The hyperkinetic syndrome in children is characterized by high levels of motor activity, lack of coordination, short attention span, inability to concentrate, lack of impulse control, nonresponsiveness to social influence, and labile emotionality. One of the most unusual aspects of the hyperkinetic child is the calming effect of a number of stimulants, particularly amphetamine and methylphenidate. In developing rats, for example, hyperactivity to amphetamine is one of the earliest drug-induced responses to appear ontogenetically, and the effects of amphetamine-related compounds are, if anything, more pronounced in young animals. Amphetamine administered to 15-day-old rats in the presence of an adult appeared to potentiate behaviors incompatible with random locomotor activity, namely, approach and contact with the anesthetized animal. When 15-day-old neonates were given amphetamine in this experimental situation, a remarkably different pattern of behavior emerged. The tendency for amphetamine to direct behavior is probably not restricted to amphetamine and its derivitives.
