Pursuant to a congressional request, GAO discussed its recent report on drug abuse treatment research findings, focusing on: (1) the overall effectiveness of drug abuse treatment; (2) the methodological issues affecting drug abuse treatment evaluations; and (3) what is known about the effectiveness of specific treatments for heroin, cocaine, and adolescent drug addiction.

GAO noted that: (1) it found that large, multisite, longitudinal studies have produced considerable evidence that drug abuse treatment is beneficial to the individual undergoing treatment and to society; (2) the studies have consistently found that a substantial proportion of clients being studied report reductions in drug use and criminal activity following treatment; (3) the studies also show that clients who stay in treatment for longer periods report better outcomes; (4) however, drug abuse treatment research is complicated by a number of methodological challenges that make it difficult to accurately measure the extent to which treatment reduces drug use; (5) in particular, growing concerns about the validity of self-reported data, which are used routinely in the major evaluations of drug abuse treatment, suggest that the treatment benefit reported by these studies may be somewhat overstated; (6) in addition, the research evidence to support the relative effectiveness of specific treatment approaches or settings for particular groups of drug abusers is limited; and (7) while one specific treatment approach--methadone maintenance--has been shown to be the most effective treatment for heroin addiction, research on the best treatment approach or setting for cocaine addiction or adolescent drug users is less definitive.