Date of Award


Degree Type


Degree Name

Master of Arts in Psychology



First Advisor

James O. Prochaska


The present study was designed to explore motivations among drug addicts in treatment by assessing stages of change and coercion experienced when seeking or participating in treatment. This study entailed the use of measures based on the Transtheoretical Model of Change and the development of a self-report instrument to assess individuals' perceived coercion from external factors that were involved in their decisions to enter drug abuse treatment. Coercion was defined as a condition under which individuals were forced by some external factors (such as events, authorities or significant others) to comply with a demand that conflicted with their personal beliefs and interests. Perceived coercion that an individual experiences is believed to have direct influence over one's commitment to treatment, length of stay in treatment and treatment outcome; however these factors have not yet been explored nor taken into consideration in research.

Subjects were 230 clients recruited from three drug addiction treatment settings: detoxification center, outpatient methadone maintenance, and residential. In Section 1 of the study, a self-report instrument to assess perceived coercion was developed. The inventory consisted of two scales: Relevance and Helpfulness. Reasonable reliability and internal validity were demonstrated. In addition, the reliability and internal validity of the measures based on the Transtheoretical Model of Change were examined. The instruments were shown to be reasonably successful in adapting to the drug addict population in the current investigation.

In Section 2, two approaches to establish stages of change among drug addicts in treatment were compared. One was the use of a discrete stage algorithm and the other was using cluster analysis of the Stages of Change Questionnaire. The two approaches involved staging individuals into subgroups through a discrete versus continuous manner. Multivariate and univariate analyses of variance, and discriminant function analysis were used to test the external validity of the stages of change against the decisional balance measures for being in treatment and quitting drugs. The approach using cluster analysis was shown to yield more appropriate stages of change subgroups.

In Section 3, measures of perceived coercion including the Relevance and Helpfulness scales and two global items on perceived control and coercion were subjected to further analyses on their relationships with the stages of change and the decisional balance measures in order to assess the external validity of the measures. The expected relationship between perceived coercion and the stages of change using the two global items asking directly on perceived control and perceived coercion for treatment participation was supported. Individuals in the precontemplation cluster reported less control over and more coerced feeling than those in the action/maintenance cluster. The construct validity of the Relevance and the Helpfulness scales to measure perceived coercion was questionable. However, precontemplators were different from those who were in action/maintenance in that they saw the factors related to family and finances were significantly less relevant to their treatment participation. Limitations of the study and future directions are discussed.



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