Date of Award


Document Type

Doctoral Research Project

Degree Name

Doctor of Psychology (PsyD)



First Advisor

Patrick J. Aragon

Second Advisor

Victoria M. Follette

Third Advisor

A. Celeste Harvey

Fourth Advisor

Lisa A. Steelman


The ever-increasing rates of prescription drug utilization in the United States, coupled with the high rates of non-adherence to psychotropic medications by patients, makes this area of research an increasingly important field of study. Previous studies have elucidated the critical factor medication adherence plays in the effectiveness of treatment and overall clinical outcomes for patients and the deleterious effect of non-adherence; one of them being substance (ab)use. The present study was conducted in an effort to add to the existing literature examining medication nonadherence and substance use. The current study looked to expand the research examining the relationship between substance use and non-compliant medication behavior, as well as evaluate the effect of intensity of substance use on non-adherence among a community mental health setting. Results of our study found 73 percent of participants engaged in illicit drug and alcohol use, and 50.3 percent of participants reported being non-adherent to medications. Contrary to the previous research, the current study found substance use had no significant effect on medication non-adherence, t(195) = -.64, p = .57. Additionally, intensity (frequency) of substances used had no significant effect on non-adherence to psychotropic medication, t(163) = 1.18, p = .24. Lastly, no relationship was found between the intensity (frequency) of substances used and non-adherence to psychotropic medication, r(163) = - .11, p > .05. Results obtained in this study continue to highlight the high frequency of patients utilizing substances concurrently with prescribed medications. Although the current study did not find substance use and intensity of use to have a statistically significant effect on medication non-adherence, the information gathered throughout this study remains important not only for medical professionals but also clinicians. Gaining a greater understanding of the factors influencing non-adherence is advantageous in the development of strategies to increase adherence in patients and improve overall patient outcomes.