Doctor of Philosophy, Case Western Reserve University, 2018, Psychology

The observation that general cognitive ability measured in children raised in higher socioeconomic status (SES) homes is more heritable than when measured in children raised in lower SES homes has been found in samples collected in the United States (Tucker-Drob & Bates, 2016). Relatively fewer studies have examined the moderating role of SES on the etiology of academic achievement. The present study seeks to explore the effects of this gene x SES interaction and a possible shared environment x SES interaction in a sample of twins participating in the Western Reserve Reading and Math Project. Data from five time points representing ages 8 to 15 with math achievement measures (N=222-528) and reading achievement measures (N=280-498) were used to assess the effects of SES (measured at the family, neighborhood, and school level) on estimates of the contribution of genetics, shared environment, and nonshared environment on variation in achievement. Significant moderation of genetics, shared environment, and non-shared environment were found for math achievement at ages 10.9 and 15.1 and for reading achievement at age 10.9. The significant effects were found in the opposite direction of those found for general cognitive ability: genetics accounted for more variation in the achievement outcome at the lowest end of SES than at the highest end of SES, and the shared environment accounted for more variation in achievement at the highest end of SES than at the lowest end of SES.

Committee: Lee Thompson Ph.D. (Committee Chair); Robert Greene Ph.D. (Committee Member); Brooke Macnamara Ph.D. (Committee Member); Jeffrey Albert Ph.D. (Committee Member) Subjects: Psychology

MS, University of Cincinnati, 2007, Medicine : Epidemiology (Environmental Health)

Background: Lead exposure, a dopamine receptor D4 polymorphism (DRD4-7), and sex have been linked to ADHD or ADHD-related neuropsychological deficits. Interactions between these three factors are biologically plausible, but have not been previously examined. Methods: DRD4 genotype and 60 month blood lead level were assessed in 172 children. At 66 months, children were administered measures affiliated with spatial working memory, rule learning and reversal, spatial span, and planning. Multivariable analyses were used to examine main effects and interactions of lead, DRD4, and sex on these executive functions. Results: DRD4-7 was associated with poorer spatial working memory, and incryeasing blood lead levels were associated with impaired rule learning and reversal, spatial span, and planning. Lead's adverse effects on planning and rule learning and reversal were seen primarily for boys. In addition, lead's impact on rule learning and reversal was evident predominately for those lacking DRD4-7. Conclusions: We observed independent effects of DRD4-7 and lead on various executive functions, and modifications of lead s effects by DRD4 genotype and sex. This study offers a model for examining how genes, toxicants, and sex interact to shape the endophenotypes underlying ADHD.

Committee: Dr. Bruce Lanphear (Advisor) Subjects: Psychology, Cognitive

Doctor of Philosophy, The Ohio State University, 2012, Psychology

Background: Depressive symptomatology has been associated with polyunsaturated fatty acid (PUFA) levels in diet and tissue. However, results have been mixed, and studies have failed to account for genetic factors that may influence such associations. Tissue PUFA levels are strongly influenced by elongase and desaturase activity, which are governed by the fatty acid desaturase (FADS) genes. Inefficient desaturase activity has been associated with depression. Further, FADS genotypes have been associated with neuropsychological phenotypes such as postpartum depression. Given these associations, the study of relationships among dietary PUFA intake, FADS genotype, and mood symptoms is warranted. Aims: The present study investigated associations among dietary intake of PUFAs, the rs174575 polymorphism of the fatty acid desaturase (FADS2) gene, and psychological outcomes. The primary aim was to determine if FADS2 genotype interacts with omega-3 (n-3) and omega-6 (n-6) PUFA dietary intake to influence associations with depressive symptoms, anxiety symptoms, anger, hostility, neuroticism, or optimism. Methods: A sample of 172 female undergraduate students provided genetic material from buccal cells, and completed a food frequency questionnaire and self-report measures including the Center for Epidemiological Studies Depression Scale, PROMIS Anxiety and Anger Scales, Cook Medley Hostility Scale, NEO Neuroticism Scale, and LOT-R Optimism Scale. Results: The main finding was that higher n-3 intake was associated with greater hostility. However, n-3 intake was not related to depressive symptoms, anxiety, anger, neuroticism, or optimism, nor was n-6 intake. Further, genotype did not interact with PUFA intake for any psychological outcomes. Conclusion: This study provided no evidence that the rs174575 fatty acid desaturase polymorphism influences associations between PUFA intake and mood.

Committee: Janice Kiecolt-Glaser PhD (Advisor); Charles Emery PhD (Committee Member); Ruchika Prakash PhD (Committee Member) Subjects: Psychology

Master of Arts, The Ohio State University, 2010, Psychology

The short (s) allele of the serotonin transporter gene length polymorphism (5-HTTLPR) is associated with depression when combined with stress, in a gene by environment interaction model. This research examined the relationship between the 5-HTTLPR gene and caregiving stress on symptoms of depression in postmenopausal women. The sample included 105 female controls and 79 female dementia caregivers. Depressive symptomatology was assessed with the Center for Epidemiologic Studies Depression Scale (CES-D). Results showed that the gene by environment interaction was not significant (p=0.167) in postmenopausal women, although there was a main effect for caregiver status, such that caregivers showed higher CES-D scores than controls (p<0.001). When comparing premenopausal women to postmenopausal women, the three-way gene by environment by menopausal status interaction was not significant (p=0.711), nor was the gene by environment interaction (p=0.140). However, there was a main effect for caregiver status such that caregivers exhibited higher CES-D scores compared to controls (p=0.003). Results suggest that postmenopausal women undergoing caregiving stress exhibit higher levels of depressive symptomatology regardless of genotype, and that female caregivers are more depressed than female controls regardless of menopausal status.

Committee: Janice Kiecolt-Glaser Ph.D. (Advisor); Charles Emery Ph.D. (Committee Member); Michael Vasey Ph.D. (Committee Member) Subjects: Psychology

Master of Sciences, Case Western Reserve University, 2008, Epidemiology and Biostatistics

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease known to have both environmental and genetic causes. The presences of these multiple factors can make the identification of genes for complex diseases, like lupus, complicated. The inclusion of environmental factors into the genetic models can play an important role in the localization of disease genes. We conducted a genome-wide linkage scan for SLE, body mass index (BMI), and SLE using BMI as a covariate, including European American and African American population subsets. The analysis used three approaches: Haseman-Elston Variance-Component-based (SIBPAL, S.A.G.E.[v5.4]), One parameter Conditional Logistic Regression-based (LODPAL, S.A.G.E.[v5.4]) and Ordered Subset Analysis Stratum-based (OSA, OSA[v2.1]) method. We found suggestive evidence for candidate regions on chromosomes 3q29, 6q26-27, and 13p11.3-q11 in the European American population and on chromosome 20p13-12 in the African American population. These results support a potential role of obesity in the etiology of lupus.

Committee: Courtney Gray-McGuire PhD (Advisor); Courtney Gray-McGuire PhD (Committee Chair); Robert Elston PhD (Committee Member); Catherine Stein PhD (Committee Member) Subjects: Epidemiology