The COVID-19 pandemic has generated alarming increases in psychological distress and alcohol use behaviors and has caused the greatest increases in depression and anxiety symptoms among college students. Prior studies have examined the impact of COVID-19 broadly on mental health and alcohol use outcomes; however, few studies have examined these impacts in college students. Previous studies have examined individual factors that could moderate the relation between COVID-19 related stressors and mental health and alcohol use outcomes, but knowledge is lacking regarding the role of emotion regulation. The present study aimed to examine the role of emotion regulation in the relation between both COVID-19 stressful experiences and COVID-19 related worry and mental health and alcohol use outcomes, and to explore racial/ethnic differences in their associations. Four hierarchical multiple regression models were conducted to assess main effects of COVID-19 stressors and emotion regulation, as well as moderation of the effect of emotion regulation on depression symptoms, anxiety symptoms, alcohol consumption, and alcohol use disorder (AUD) symptoms during the past year. COVID-19 related worry was associated with greater symptoms of both mental health outcomes, whereas COVID-19 related stressful experiences were associated with both mental health outcomes, more alcohol consumption, and more AUD symptoms. Difficulties in emotion regulation had significant main effects on mental health outcomes and AUD symptoms, but not alcohol consumption. Hispanic/Latinx students reported higher experiences of both COVID-19 related stressors, but consumed less alcohol than did White/European students. This study provides further insight into the nature of COVID-19 related stressors and their subsequent impacts. Implications for prevention and intervention on college campuses are discussed.

This project is an investigation of the gene by environment (GxE) interactions’ effect on substance use outcomes among refugee communities. Substance use disorders (SUDs) are a major public health concern, affecting individuals and communities worldwide. The etiology of SUDs is complex, involving a combination of genetic, environmental, and social factors. In recent years, there has been growing interest in the role of gene by environment interactions in the development of SUDs, particularly in vulnerable populations such as refugees. Refugee populations are exposed to a range of environmental stressors that may interact with genetic factors to increase their risk of SUDs. However, a number of studies describe a “refugee paradox,” where despite having been exposed to risk factors that can lead to SUDs, they are less likely to develop SUDs. Understanding these gene by environment interactions in refugee communities is crucial for not only understanding this phenomenon, but developing effective prevention and treatment strategies for this population. This thesis aims to investigate the gene by environment interactions underlying substance use in refugee communities and to analyze different methods for gene by environment analyses, ultimately determining which method is best suited for this population.