This thesis attempts to use psychoneuroimmunology (PNI) as a lens for examining different immune and autoimmune disorders, as well as psychological function and dysfunction. Through this examination, it is hypothesized that PNI could point to an accurate theoretical framework for describing the mind-body relation, or at the very least gain a deeper respect for showing the complexity of consciousness and health. Conversely, an appropriate view of the mind-body relation should provide a sound theoretical framework for PNI research.

Chronic pain, or reoccurring pain lasting longer than three months, is frequently co- morbid with other chronic conditions. Physiological health problems such as overall general health, immune function, inflammation, stress, and sleep, as well as psychological problems like depression and anxiety are all associated with chronic pain. Previous studies have also shown evidence for the heritability of chronic pain, indicating a genetic factor for chronic pain in children. However, few studies have investigated potential epigenetic processes involved in childhood chronic pain. DNA methylation and other epigenetic processes are highly susceptible to changes during crucial developmental periods in children, and they are heavily influenced by psychosocial factors and environmental factors. During an immune response, various cytokines such as TNFα, IL-6, and CRP are released. Cytokines are involved in the production of pain through their pro-inflammatory properties. Additionally, there is evidence to believe they increase pain sensitivity acutely by acting directly on nociceptors. Previous studies have shown that higher levels of inflammatory cytokines are associated with more pain because the inflammatory response from our immune cells activates pain pathways. A constant or prolonged activation of the immune response may consequently result in chronic pain. In many cases of chronic pain, there is an increase in the circulating pro-inflammatory cytokines in the blood that also leads to hypersensitivity.

For my thesis, I conducted a study on a healthy pediatric cohort to investigate how DNA methylation of genes related to myelin may predict total white matter volume in a healthy pediatric cohort. The relatively new field of neuroimaging epigenetics investigates how methylation of genes in peripheral tissue samples is related to certain structural or functional features of the brain, as measured by neuroimaging data. Research has already demonstrated that methylation of genes in peripheral tissues is related to a variety of brain disorders. We hypothesized that methylation of myelin-related genes as measured in saliva samples would predict total white matter volume in a healthy pediatric cohort. After processing DNA methylation data from saliva samples from participants, multiple linear regressions were ran to determine if DNA methylation of myelin related genes was related to total white matter volume, as measured by data from structural MRIs. Results showed that these genes, which included MOG, MBP, and MYRF, significantly predicted total white matter volume. Two genes that were significant in our results have been previously shown to produce proteins that are essential to the structure of myelin.