3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Early and subsequent life stress: physiological responses, moderating events and outcome(2015-03-27) Muller, Denise Margaret54 225: crimes against children reported in 2010/2011 28 128: sexual offences 30% of the sexual offences occurred in children younger than ten years. These figures are a stark reminder of the growing number of children who experience deprivation, abuse and maltreatment in South Africa (Unicef, 2013). Although controversy exists with the reporting methods and the accuracy of recall in adult patients, it remains evident that a significant number of female children are sexually abused. Associations between early life stress and later life dysregulation of the hypothalamic-pituitary-adrenal axis hormone, cortisol, and the immune system cytokine, interleukin 6, have been found in adult patients and in animal studies. Importantly, although there is also evidence that early life stress results in later life neurobiological changes, we have to date, no identifiable biological markers to assist with diagnosis or to inform treatment strategies in young children who present with early life stress such as sexual abuse or maternal neglect. Thus, there is a growing imperative to establish whether the potential precursor biomarkers are evident in early in development following adverse life conditions. Therefore the research focus of the thesis was to investigate (1) whether dysregulation of the HPA axis is evident in young children who are exposed to the traumatic stress of abuse, (2) whether there is evidence that inadequate maternal care, during the neonatal stage of development, has an impact of HPA and immune function and consequently onItem Personality style, cortisol secretion and the inflammatory response to trauma exposure in a cohort of South African metro police cadets: a prospective, longitudinal study(2012-01-17) Subramaney, UgasvareeLiterature investigating trauma exposure, Posttraumatic stress disorder (PTSD) and cortisol secretion has produced conflicting results with regard to whether cortisol is increased or decreased. With trauma there is also a pro- inflammatory response which is intimately linked with the hypothalamic pituitary axis (HPA). The police population can offer useful information in this regard as they represent a sample that will undergo exposure to traumatic events as part of their normal duties. In South Africa few studies have examined biological correlates of the traumatic stress response in the police population. This study sought to determine whether correlations exist between cortisol and the inflammatory response in terms of the cytokines Interleukin 6 (IL6) and Tumour Necrosis Factor (TNF) in response to trauma exposure in a cohort of newly enrolled metro police officers, previously naïve to the duty related trauma exposure. Personality styles were assessed, as coping skills and personality have been suggested as factors determining responses to trauma. The study participants were followed up for one year with repeated measures analysis of urine, blood, and saliva cortisol as well as blood cytokine determination every 3 months. Measures for PTSD [the Clinician Administered Scale for Posttraumatic stress disorder (CAPS) and the revised version of the Impact of Event Scale (IES-R)] as well as for depression [the Hamilton Depression Rating Scale (HAM-D)] were undertaken. 145 new recruits volunteered for the study, of which 120 completed all 5 visits. There were slightly more females than males in the sample and almost 50% of the sample admitted to alcohol abuse. Trauma exposure on entry into the police force was remarkably high with 99% having been exposed to at least one traumatic event in their lives. The majority (61.1 %) had been exposed to more than one traumatic event. There was evidence for the influence of prior trauma on responses to current traumatic events. MVA’s were very common, both duty and non duty related. Certain traumas were associated with greater changes in scores for PTSD and depression in relation to baseline. Over the 5 visits, only a third submitted valid 24 hour urine samples. Of these, the profile of the entire group indicated that 24 hour urine cortisol tended to initially decrease, and then increase with time. Saliva and blood cortisol, which were more reliably measured, tended to decrease with time. Scores for depression and post traumatic stress disorder were generally low in response to duty related traumatic events, and tended to decrease over time. However, the prevalence of lifetime PTSD as measured by the CAPS was high. There was a strong linear correlation between TNF and IL6. Results indicate a proinflammatory response, particularly with regard to IL6. There were no significant correlations between blood cortisol and HAM-D and between blood cortisol and CAPS (lifetime). There was an inverse relationship between CAPS (current scores) and blood cortisol. Cortisol and IES-R scores were significant at visit 3 (inverse relationship). For saliva, there were no significant associations with any of the variables for PTSD and depression. For personality styles, aggressive and antisocial clinical patterns were associated with lower current CAPS scores, while schizoid clinical pattern and the severe syndrome scale of thought disorder showed an association with lower lifetime CAPS score. For the IES-R, only narcissistic clinical pattern was associated with lower scores. A further analysis of those with low (less than 25% of the median) and high (greater than 25% of the median) cortisol responses was undertaken. The results indicate a similar trend to some studies showing lowered cortisol levels with chronic trauma exposure, but this did not correlate with sufficiently high scores for PTSD as measured by the CAPS. Similarly, proinflammatory cytokine increases are evident with trauma exposure, but not with scores for PTSD and depression. There were more variables significantly associated with the low cortisol responders than the high cortisol responders; with a suggestion of cumulative trauma exposure correlating with low cortisol response and a corresponding pro inflammatory response in terms of IL6. The results are discussed with a view to assisting the metro police force with recruitment and counseling strategies and important future research is recommended.