CROSS-SECTIONAL STUDIES OF ADULT SOCIOPATHS AND HYPERACTIVE CHILDREN REPORT SIMILAR CLINICAL, ELECTROENCEPHALOGRAPHIC, NEUROPHYSIOLOGICAL, BEHAVIORAL, AND PSYCHOLOGICAL ABNORMALITIES IN THESE TWO PSYCHIATRIC SYNDROMES. LONGITUDINAL STUDIES OF CHILDREN WHO LATER BECAME SOCIOPATHIC SUGGEST THAT THE SUBJECTS SUFFERED FROM CHILDHOOD PROBLEMS SIMILAR TO THOSE OF HYPERACTIVE CHILDREN. FOLLOWUP STUDIES OF HYPERACTIVE CHILDREN IN THEIR EARLY AND MID TEENS REPORT SERIOUS DELINQUENT BEHAVIOR OF THE TYPE THAT OFTEN PREDICTS ADULT CRIMINAL BEHAVIOR. FAMILY STUDIES SHOW EXCESSES OF THE SAME PSYCHIATRIC DISORDERS (ALCOHOLISM, SOCIOPATHY, HYSTERIA) IN THE FAMILIES OF HYPERACTIVE CHILDREN AND SOCIOPATHIC ADULTS, AN INDICATION OF A FAMILIAL RELATIONSHIP BETWEEN CHILDHOOD HYPERACTIVITY AND ADULT SOCIOPATHY. TREATMENT WITH STIMULANT DRUGS IS EFFECTIVE IN REDUCING ANTISOCIAL BEHAVIOR AND IMPROVING INTELLECTUAL FUNCTIONING IN HYPERACTIVE CHILDREN, BUT THE EFFECT OF MEDICATION ON THE SUBSEQUENT BEHAVIOR OF THESE CHILDREN IN ADOLESCENCE AND ADULTHOOD IS NOT KNOWN. FURTHER LONG-TERM, CLINICAL, AND FAMILY STUDIES OF HYPERACTIVE CHILDREN, PARTICULARLY OF THE LONG-TERM EFFECTS OF STIMULANT DRUG TREATMENT, ARE NEEDED. A LIST OF REFERENCES IS INCLUDED. (AUTHOR ABSTRACT MODIFIED--LKM)