Retention in treatment--indicator or illusion: an essay.

This article poses questions about the meaning of retention in substance user treatment. Retention has become a "gold standard" for substance user-treatment programs, suggesting it has become more than an indicator of positive outcomes, but a positive treatment outcome in its own right. Retention has been studied in numerous ways and has been associated with positive treatment outcomes, but questions remain about whether it has assumed greater importance than it merits. For example, it may be an artifact of other client personality characteristics that are also associated with more positive outcomes. Conversely, it may be a function of the interaction of treatment environment and client. This article suggests a need to broaden the scope of treatment-retention studies and to compare retention rates across other medical treatment environments to see if failure to complete treatment is a function of substance user treatment or of all treatment processes as well as other types of planned change processes.