Biological validation of the hyperkinetic syndrome.

Biological evidence for the hyperkinetic syndrome is reviewed and evaluated. Research data from anatomical, genetic, physiological and pharmacological studies consistently yield weak or non-specific relationships between biological factors and hyperactivity. While such findings suggest an organic basis for at least some subgroups of hyperactive children, criteria for selection of subjects in past research have not been sufficiently well-established to allow such biological factors to be linked with specific behavioral symptoms. Thus there is no compelling evidence for the existence of the syndrome; there is merely an array of general correlations between biological alteration and non-specific deviant behavior. Alternative interpretations of this situation are presented.