Date of Submission


Degree Type


Degree Name

Doctor of Psychology (PsyD)



Department Chair

Robert A DiTomasso, PhD, ABPP, Chair, Department of Psychology

First Advisor

Petra Kottsieper, PhD, Chairperson

Second Advisor

Stephanie H Felgoise, PhD, ABPP

Third Advisor

Catherine Barber, PhD


This qualitative study examined the factors that affect treatment adherence and service engagement in individuals with serious mental illnesses (SMI). A semistructured interview was used to collect data from treatment adherent and treatment nonadherent adults with SMI. What factors make one more or less likely to disengage from treatment? What boundaries stand in the way of quality mental-health care, and how do adults with SMI overcome these barriers? Service engagement in the population with SMI in the study was explained according to three healthcare behavioral models, the health belief model, the network episode model, and the demoralization framework model. Data collected from the narratives of 12 participants suggest that provider factors, including treatment style, theoretical orientation, and communication style, can be protective factors against systemic barriers. In light of the results of narrative data, health behavioral models that emphasize process-oriented behaviors in consideration with a broader social structure are better predictors of healthcare engagement than are rational, value-expectancy models.