Factors that make assessment of adolescent drug use difficult include youths' cognitive immaturity; the possible lack of negative consequences due to the relatively short history of alcohol or other drug abuse; and the presence of other psychological, familial, and social dysfunction that may have existed before the drug abuse or been caused by it. Screening for drug abuse should take place as part of routine health care, during the entry into mental health counseling, as part of the evaluation process for deteriorating academic performance, and as part of the intake process into the juvenile justice system. A complete assessment requires family involvement, but basic interview screening can often be completed in one or two sessions. Formal screening instruments can be helpful for a professional with limited time. Several treatment approaches are available for adolescents, all based on the disease model of chemical dependency. Lists of questions, checklist, and 92 references