Although much has been achieved during the last decade in the area of drug abuse, drug abuse still remains a major social, economic and political problem and continues to receive a significant amount of attention from policy-makers and researchers. Treatment facilities have vastly expanded their capabilities over the years, accepted treatment techniques continue to be refined, and new treatment techniques have been developed. This paper highlights the more significant lessons that have been learned over the last decade about drug abusers and their treatment, reviews past research related to drug treatment programs and their effectiveness, and notes the future directions for clinical research that have been proposed by the National Institute on Drug Abuse. (Author/MP)