Doctor of Philosophy (PhD)
Dr. Julia F. Houfek
Most individuals experience at least one potentially traumatic event (PTE), such as a natural disaster. When exposed to PTEs, some individuals are more vulnerable to develop psychopathology, such as Post-Traumatic Stress Disorder (PTSD). In contrast, others are less adversely affected by PTEs, who are often described as “resilient”. A concept analysis of resilience (Manuscript #1) revealed: the antecedent is PTE; the defining attributes are ego-resiliency, emotion regulation, heredity, and social support; and the consequences are none to mild psychopathological symptoms and positive adaptation. Based on a systematic review of genetic influence on resilience (Manuscript #2), the following 10 polymorphisms were identified as candidate genes associated with resilience and selected in this study: rs25531 in 5-HTTLPR, rs4680 in COMT, rs6265 in BDNF, rs1800955 in DRD4, rs1800497 in DRD2, rs53576 in OXTR, rs4606 in RGS2, rs1006737 in CACNA1C, rs9296158 in FKBP5, & rs7209436 in CRHR1. A total of 450 college students participated in this dissertation study (Manuscript #3), completed questionnaires, and donated their buccal cells to extract DNA for genotyping. The results indicated individuals exhibited lower resilience outcomes (i.e., more psychological distress and less positive adaptation) as they experienced more PTEs. However, the effect of PTEs on resilience outcomes was weaker among individuals with high ego-resiliency, strong emotion regulation flexibility, high perceived social support, and the Val allele(s) of rs4680 in COMT. Additionally, the effect of unfavorable physical and sexual experiences on resilience outcomes was weaker among individuals with the G allele(s) of rs4606 in RGS2, the T allele(s) of rs7209436 in CRHR1, and higher scores (i.e., more major alleles) of a Polygenic Susceptibility Score. Major limitation is the cross-sectional design of this study because it cannot assess resilience over the time. In a future study, additional candidate genes associated with resilience need to be investigated, preferably with a longitudinal design among individuals exposed to more specific PTEs. Furthermore, if collaboration with other researchers is possible, a systematic approach, such as Genome-Wide Association Study (GWAS), can be considered.
Niitsu, Kosuke, "Genetic Influence on Resilience to Potentially Traumatic Events" (2017). Theses & Dissertations. 205.
Available for download on Saturday, April 28, 2018