University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 12-2020 An Exploratory Study of Varying Phenotypes of Posttraumatic Stress Among a Comorbid Substance Misuse Population Dennis Allen Donahue [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Other Psychology Commons Recommended Citation Donahue, Dennis Allen, "An Exploratory Study of Varying Phenotypes of Posttraumatic Stress Among a Comorbid Substance Misuse Population. " PhD diss., University of Tennessee, 2020. https://trace.tennessee.edu/utk_graddiss/6068 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Dennis Allen Donahue entitled "An Exploratory Study of Varying Phenotypes of Posttraumatic Stress Among a Comorbid Substance Misuse Population." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Psychology. Gina P. Owens, Major Professor We have read this dissertation and recommend its acceptance: Erin E. Hardin, Jennifer A. Morrow, Dawn M. Szymanski Accepted for the Council: Dixie L. Thompson Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) An Exploratory Study of Varying Phenotypes of Posttraumatic Stress Among a Comorbid Substance Misuse Population A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Dennis Allen Donahue December 2020 ii Copyright © 2020 by Dennis Allen Donahue All rights reserved. iii Dedication For all who have struggled to find recovery. iv Acknowledgements I would like to first give special thanks to all of my many mentors, battle-buddies, and brothers and sisters in the Blount County, TN recovery community. You have provided selfless support in almost every way possible. The concept for this project was born out of our combined work, and it could not have materialized to this point without your active engagement and assistance. You are now and always will be home to me. I would like to express my absolute admiration and gratitude to my advisor, Dr. Gina Owens, on whom I could always count for steady guidance and unwavering support. I am truly blessed to have taken this journey with you. Thank you also to my committee members—Drs. Erin Hardin, Jennifer Morrow, and Dawn Szymanski–for your patient counsel, flexibility, and accessibility. And, to all my friends and colleagues during my time in Knoxville, TN and Jackson, MS, the difference between floating and drowning is less about how hard we kick than about what (or whom) we choose to pull near. As always, my love and appreciation to my incredible family and friends who continuously challenge me to reach and grow, even if it means sometimes falling; and, without whose eternal support and guidance, I may not have gotten back up many of those times. In particular, thank you to my wife, Melisa, and our children—Blaine, Cherish, and Cian. You are my motivation for everything. And, my eternal love, respect, and appreciation to my parents Ken and Carmen, who have always taught me to be independent, think critically, and question everything. v Abstract Objective: The purpose of this study was to explore differences in presentation of posttraumatic distress (PTD) that may represent different phenotypes, such as a possible cognitively-driven variant, in addition to those rooted in the prevailing conditioned-fear model. In conjunction, links to substance misuse and a purposeful selection bias for specific drugs-of-choice (DoC) based on phenotype variation were examined. Method: A convenience sample of inpatients in residential treatment for substance misuse who also endorsed posttraumatic distress following at least one previous traumatic experience (N = 177) completed self-report assessments and an in-person direct inquiry. Results: Hierarchical cluster analysis and ANOVA results partially supported our hypotheses and provided some evidence of a cognitive-focused phenotype, as well as a possible image/adrenergic-based phenotype. Subsequently, multinomial logistic regression determined that the hypothesized phenotypes were significantly linked to DoC selection, specifically (a) cognitive-focused phenotype predicted primary alcohol/benzodiazepine use (b) image/adrenergic-based phenotype predicted cannabinoid/opiate use, and (c) a traditional “mixed” PTD presentation predicted polysubstance use. Conclusions: Findings from this exploratory study offer additional validation to calls for continued examination of varying phenotypes, as well as a cognitively-driven model, of PTD additional to those based in conditioned-fear. Additionally, evidence was shown for a purpose-driven theory of substance misuse, hallmarked by an underlying maladaptive drive to select a DoC with the capacity to alleviate specific symptomatology (e.g., heavy alcohol use to alleviate excessive rumination and sleep disturbance). Keywords: cognitive, adrenergic, posttraumatic distress, drug-of-choice, substance misuse vi Table of Contents Chapter 1: Introduction ................................................................................................................... 1 Traditional Model of Posttraumatic Distress .............................................................................. 3 Calls for Reconceptualization of PTD ........................................................................................ 6 A Purpose-Driven Theory of Substance Misuse ......................................................................... 9 Purpose of the Present Study ..................................................................................................... 12 Chapter 2: Method ........................................................................................................................ 14 Participants ................................................................................................................................ 14 Measures .................................................................................................................................... 14 Procedure ................................................................................................................................... 19 Data Analysis ............................................................................................................................ 20 Chapter 3: Results ......................................................................................................................... 23 Preliminary Analysis ................................................................................................................. 23 Hypothesized Phenotypes and Variations in PTD .................................................................... 24 Relationship between PTD and DoC ........................................................................................ 25 Chapter 4: Discussion ................................................................................................................... 28 Varying Phenotypes of PTD ..................................................................................................... 28 PTD Phenotype's Link to DoC .................................................................................................. 30 Limitations ................................................................................................................................ 31 Future Research Directions ....................................................................................................... 34 Clinical Implications ................................................................................................................. 35 Conclusions ............................................................................................................................... 36 References ..................................................................................................................................... 38 Appendix ....................................................................................................................................... 56 Study Informed Consent Document .......................................................................................... 63 Vita ................................................................................................................................................ 66 1 CHAPTER 1: INTRODUCTION When individuals perceive events as threatening, they may experience a variety of physiological effects stemming from the traumatic stress response, including increased adrenergic responding and cognitive hyper-attentiveness or even potential dissociation (see Sapolsky, 2004; van der Kolk et al., 2012). The various features of this internal process allow for the behavioral responding (e.g., fight-flight-freeze responses) needed to react to a potential threat. Following removal of the threat or when the situation resolves, the physiological effects of the traumatic