The instrument contains 150 items and is used in a structured interview format. It is modeled after the Addiction Severity Index used for adults. The interviewer uses 10-point severity ratings, and composite scores are developed for each of 9 life problem areas that are often relevant to the treatment needs of adolescent drug abuse clients. These life areas are medical, school, employment, social, family, psychological, legal, alcohol, and drugs. A standardization sample for the instrument consisted of 1,042 youths admitted to 6 outpatient programs, 3 residential nonhospital programs, and 3 hospital programs. Experience with the instrument indicates that the use of ADAD can improve matching of individual adolescents with treatment settings and types of programs and can aid in the development of an individualized treatment plan. Tables and 17 references.