In the last few years, a vast amount of research has accumulated with respect to American children's use of legal and illicit drugs. This research has included cross-sectional studies (which have attempted to determine current drug usage, age of onset for each drug used, and maximum frequency of use in the lifetime); longitudinal studies (which have attempted to predict which children would become future drug users); and other evaluation studies (which have searched for ways to prevent or reduce drug use). Indeed, today we know more about children's drug use than we know about any other type of adolescent psychopathology. However, it is not clear to what extent illicit drug use is psychopathology. The present paper, after reviewing what is known about the frequency with which various types of drugs are used by young people, raises the question of the extent to which illicit drug use appears to be pathological, either in terms of its predictors or its consequences. Topics reviewed include age at first use, popularity of different drug classes, motivation for use, heavy drug use, trends in use, correlates and predictors of drug use (e.g., sex differences and socioeconomic status), and drug users compared with delinquents. (Author/MP)