Patterson: Copyright (and its

As the field of chemical dependency treatment has changed and evolved over the past decade, so has the perception of the importance of the motivation of persons entering into treatment. Two theories focus on motivation in substance abuse: Self-determination theory and the Transtheoretical Model of Change. Self-determination theory provides a theoretical basis for the source of motivation, and outlines a continuum of motivation from amotivation to external motivation to internal motivation. The Transtheoretical Model of Change describes stages, processes, and levels of change. The purpose of this research was to explore the relationship between Self-determination theory and the Transtheoretical model of change. Specifically, Self-determination theory was operationalized as internal or external source of motivation, and the Transtheoretical model was operationalized as the stages of change: precontemplation, contemplation, and action. The second purpose of this research was to examine the relationship between source of motivation and chemical dependency treatment outcome, measured both as use after intake and treatment completion. Data used for this study were from the Drug Abuse Treatment Outcome Stud