The survey provided estimates of the prevalence of use of a variety of illicit drugs, alcohol, and tobacco and used a nationally representative sample of the civilian noninstitutionalized population. The 1994-96 survey also included mental health data not previously available. Approximately 13 percent of adolescents ages 12-17 years had emotional problems as indicated by withdrawal, somatic problems, anxiety, and depression. An estimated 17 percent of adolescents aged 12-17 years had behavioral problems as indicated by delinquent or aggressive behaviors. Nine percent of the youths reported using illicit drugs, 20 percent reported using alcohol, and 19 percent reported using cigarettes in the past month. In addition, the likelihood of drug use among adolescents was associated with the severity of emotional and behavioral problems across age and gender groups. The syndrome most consistently associated with drug use was delinquent behavior, followed by scales measuring social problems and attention problems. Delinquent behaviors, including stealing, swearing, hanging around with troublemakers, and running away from home, were associated with higher levels of drug use. The attention problem of feeling confused or in a fog was also associated with more drug use. Finally, adolescents who used drugs were less likely than others to acknowledge the social problems of being teased, preferring younger friends, acting too young, or being overly dependent on adults. Tables; footnotes; appended tables, methodological information, and questionnaire items; and 85 references