Many adolescent clients of the Division of Alcohol and Substance Abuse (DASA) in Washington come also with psychiatric problems, are involved with the legal system, live with someone who abuses drugs or alcohol, have poor social support networks, or live in poverty. This report describes a sample of adolescent clients who received treatment and/or assessment services funded by DASA in early 1990. Following the report's Introduction, which outlines the background, methods, report organization and limitations, the study profiles client placement into inpatient, intensive outpatient, and regular outpatient treatment modalities. Adolescents were then followed through the three stages of the treatment process: (1) assessment; (2) entry into treatment; and (3) completion of the planned treatment. Researchers compared clients assessed with a non-serious drug or alcohol problem with those considered as abusing or addicted to one or both substances. Investigators identified characteristics of clients involved with the court system and examined the differences in the characteristics and placement of clients from Eastern and Western Washington. The final chapter presents clients' results on the Personal Experience Inventory. Six appendices present statistical results and demographic information. The myriad problems of these adolescents make them a difficult group to treat--they may require an array of services of which drug and alcohol treatment is an important, but solitary, component. (RJM)