Disrupted emotion processes are central features of posttraumatic stress disorder (PTSD) and major depressive disorder (MDD), which are linked to altered neural response patterns. However, inconsistent results have led to questions about the reliability of such findings. Heterogeneous clinical presentations across individuals with PTSD and MDD are likely to be associated with heterogeneous neurobehavioral changes which may differ depending on the emotion process studied. Similarly, neurobehavioral signatures of treatment response prediction may vary based on the task or context probed. In these studies, we examined how neuroimaging of emotion processes may shed light on mechanisms underlying symptom heterogeneity in PTSD (Study 1) and how similar neuroimaging signatures may be useful for predicting response to MDD treatment (Study 2). Results showed re-experiencing and hyperarousal symptoms had opponent effects on neural habituation to negative images, such that while increasing severity of hyperarousal symptoms was related to diminished habituation, increasing severity of re-experiencing symptoms was associated with enhanced habituation. Additionally, across MDD studies, two regions of the brain, the right anterior insula and the subgenual anterior cingulate cortex, exhibited pretreatment responses to negative emotional stimuli that were predictive of clinical response to treatment. Considered together, this work demonstrates the translational utility of neuroimaging of negative emotion processes to enhance our understanding of symptomatology and treatment prediction in PTSD and MDD. / Ph.D. / People who have posttraumatic stress disorder (PTSD) or depression often notice changes in the intensity and range of emotions they experience. These changes are thought to be related to differences in how the brain processes emotional information. Using neuroimaging to visualize changes that occur in the brains of individuals with PTSD or depression when they are experiencing negative emotions, we may gain a better understanding of how their symptoms are impacting them and how they may respond to different types of treatments. In these studies, I used brain imaging to measure responses to emotional images of people with and without PTSD. I found that certain PTSD symptoms affected the way people's brains responded over time to negative and neutral images. More several arousal symptoms were linked to less decreases of brain responses over time or less habituation. More severe symptoms of intrusive memories or distress when exposed to reminders of trauma were associated with greater decreases of brain responses to negative images. In a second study, I found that across studies of people with depression, two regions of the brain that are involved in emotion processing and stress responsivity, show pretreatment responses to negative emotional stimuli that are related to how they are likely to respond to treatment for depression. Overall, my research demonstrates how brain responses to negative emotions may be useful for understanding symptoms of mental health disorders and may help with predicting how individuals will respond to treatment.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/104223 |
| Date | 14 August 2020 |
| Creators | McCurry, Katherine Lorraine |
| Contributors | Psychology, Chiu, Pearl H., Clum, George, Casas, Brooks, LaConte, Stephen M. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Dissertation, Text |
| Format | ETD, application/pdf, application/pdf |
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