Psychology Commons^™

Examining Genetically-Informed Etiologic Models Of Co-Occurring Posttraumatic Stress Disorder And Recreational Cannabis Use Among College Students, Terrell A. Hicks

Theses and Dissertations

The college years encompass a period of increased risk recreational cannabis use (RCU), as well as a time of increased risk for trauma exposure and developing posttraumatic stress disorder (PTSD). Given the high co-occurrence between RCU and PTSD, and the potentially negative consequences of the two (e.g., worse academic outcomes), there is a need to understand the etiologic mechanisms of these commonly co-occurring conditions. Two primary phenotypic models exist: self-medication model (i.e., PTSD to RCU) and the high-risk model (i.e., RCU to PTSD). To date, there are two existing studies longitudinally examining the etiologic models proposed to explain co-occurring RCU …

The Buffering Effects Of Resilience On Alcohol Use: A Phenotypic And Genotypic Investigation, Shannon Cusack

Theses and Dissertations

The college years encompass a time of vulnerability for problematic alcohol use/alcohol use disorder (AUD) and exposure to traumatic events (TE), which is a transdiagnostic risk factor for AUD, posttraumatic stress disorder (PTSD), and comorbid AUD-PTSD. However, not all who experience a TE develop these disorders, highlighting the need to identify factors that impact post-trauma outcomes. Resilience has been shown to be associated with lower alcohol consumption and related problems following TE, though the buffering effects of resilience on alcohol use have not yet been examined. Further, twin studies demonstrate that resilience is moderately heritable, but further research is needed …

Genetics And Alcohol Interventions In Youth, Zoe E. Neale

Theses and Dissertations

Alcohol is the most commonly used substance among youth, and risky alcohol use is associated with harmful consequences such as accidents, academic consequences, and physical and emotional health problems. Alcohol use disorders are approximately 50% heritable, yet most efforts to prevent and intervene upon youth alcohol use focus only on environmental factors. Furthermore, current prevention and intervention programs tend to have modest effects and are not uniformly effective for all individuals. Gene-by-intervention (GxI) studies offer an opportunity to expand current understanding of interventions by examining whether underlying genetic risk may contribute to differential program effects. Much of the current GxI …

Genome-Wide Systems Genetics Of Alcohol Consumption And Dependence, Kristin Mignogna

Theses and Dissertations

Widely effective treatment for alcohol use disorder is not yet available, because the exact biological mechanisms that underlie this disorder are not completely understood. One way to gain a better understanding of these mechanisms is to examine the genetic frameworks that contribute to the risk for developing this disorder. This dissertation examines genetic association data in combination with gene expression networks in the brain to identify functional groups of genes associated with alcohol consumption and dependence.

The first study took advantage of the behavioral complexity of human samples, and experimental capabilities provided by mouse models, by co-analyzing gene expression networks …

A Genetically Informed Study Of Acute Threat Endophenotypes For Callous-Unemotional Traits, Ashlee A. Moore

Theses and Dissertations

Introduction. Callous-unemotional (CU) traits predict socially debilitating outcomes including Antisocial Personality Disorder and violent crime in adulthood. Despite significant research, the etiology of CU traits is not well understood. This dissertation incorporates genetic, physiological, neuroanatomical, and self-report measures to investigate the etiology of CU traits. Specifically, this project focuses on measures previously found to associate with impaired fear-processing observed in individuals high on CU. Brain morphometry for paralimbic regions of interest (ROIs) and electromyographic facial eyeblink reflex to startle and fear-potentiated startle probes were investigated as potential endophenotypes for CU traits. Methods. Two genetically informative (ages 9-20) twin samples ( …

Hpa Axis Genetic Variation And Life Stress Influences On Functional Connectivity In Resting State Networks, Tara Ann Miskovich

Theses and Dissertations

Stressful or traumatic experiences are a key risk factor for developing psychopathology, primarily through the impact that chronic stress has on hypothalamic-pituitary-adrenal (HPA) axis functioning. The HPA axis regulates the stress response but can become dysregulated with chronic activation and impact brain functioning. In addition to environmental stressors, genetic variation in genes in the HPA axis appear to influence HPA axis functioning and is also related to disruption in brain functioning, particularly in the context of high life stress. The current study focused on examining potential mechanisms through which trauma and stress interacts with HPA axis genes to impact key …

Structural And Functional Brain Connectivity In Middle-Aged Carriers Of Risk Alleles For Alzheimer's Disease, Laura Korthauer

Theses and Dissertations

Single nucleotide polymorphisms (SNPs) in APOE, COMT, BDNF, and KIBRA have been associated with age-related memory performance and executive functioning as well as risk for Alzheimer’s disease (AD). The purpose of the present investigation was to characterize differences in brain functional and structural integrity associated with these SNPs as potential endophenotypes of age-related cognitive decline. I focused my investigation on healthy, cognitively normal middle-aged adults, as disentangling the early effects of healthy versus pathological aging in this group may aid early detection and prevention of AD. The aims of the study were 1) to characterize SNP-related differences in functional connectivity …

Does Genotype Correlate With Phenotype? Evaluating Ruffed Lemur (Varecia Spp.) Color Vision Using Subject Mediated Automatic Remote Testing Apparatus (Smarta), Raymond Vagell

Theses and Dissertations

Ruffed lemur (Varecia spp.) color vision research was conducted using a multidisciplinary approach: psychophysics, genetic analysis, technology, and animal training. The behavioral manifestation of Varecia spp. trichromacy was shown using a touchscreen apparatus (SMARTA). Trichromats performed better than dichromats when discriminating red from green (G₂ = 78.10, p < 0.001).

Impact Of Faah Genotype And Marijuana Use On Brain Structure And Neuropsychological Performance In Emerging Adults, Skyler Gabriel Shollenbarger

Theses and Dissertations

Introduction: Chronic MJ use may be associated with higher cognitive ability impairments (see Lisdahl et al., 2013). Regions undergoing later maturation (Gogtay 2004), may be at increased risk for MJ-induced alterations. Endogenous cannabinoid signaling (ECS) is modulated by the function the enzyme Fatty Acid Amide Hydrolase (see Ho & Hilard, 2005), thus the gene encoding for this enzyme (FAAH) impacts ECS (Sipe et al., 2002). Here, we examine the impact of MJ use and FAAH genotype on PFC complexity and underlying frontal white matter (WM) integrity in young adults. Methods: Participants included 37 MJ users and 37 non-using young adults …