Examining Gene-Environment Interactions in Trajectories of Alcohol Use Disorder Symptoms Among African American College Students

• In Event: 3-117 - Incorporating Culture and Diversity in Understanding Genetic and Environmental Influences on Human Development

Integrative Statement

Alcohol use disorders are prevalent and represent significant public health concerns for all racial/ethnic groups in the United States. Numerous studies have demonstrated that genetic and environmental factors interact (GXE) to influence alcohol problems. Yet prior GXE research has primarily focused on samples of European descent. Given differences in rates of alcohol use and related consequences, environmental experiences, genetic factors, and cultural processes across racial/ethnic groups, it is important to study GXE processes that impact risk for alcohol use disorders in all racial groups so that all can benefit from the research and intervention/prevention efforts. In this study, we examined whether and how genetic risk for alcohol problems and peer deviance and interpersonal potentially traumatic events (IPTE) independently and interactively influence trajectories of alcohol use disorder symptoms (AUDsx) in a sample of African American students across the college years.
Data were drawn from the Spit for Science study. The sample included 1,119 students of African ancestry aged 18 to 24 years (M = 18.44, SD = .42; 74% female). Participants completed an online survey during the fall semester of their freshmen year and every spring semester throughout college, and provided a saliva sample for genotyping. AUDsx were measured as the number of alcohol use disorder criteria ever endorsed according to DSM-V. At each assessment, participants answered six questions about their perception of peer deviance (e.g., how many of their friends had smoked cigarette, got drunk, etc.) and experiences of IPTE including physical assaults, sexual assaults, and other unwanted sexual experiences over the past 12 months. Family history of alcohol problems was assessed by participants’ report on alcohol problems for four types of relatives: mother, father, aunts/uncles/grandparents, and siblings. Alcohol dependence genome-wide polygenic scores (AD_GPS) were calculated using estimates from the largest published genome-wide association study of alcohol dependence for African Americans to date (Gelernter et al., 2014). Multilevel growth models were conducted to examine the effects of genetic risk predispositions, environmental factors (i.e., peer deviance and IPTE), and their interactions, in predicting trajectories of AUDsx. Participants’ age and sex were included as covariates, along with genetic ancestry principal components to account for population stratification.
Results indicated that AD_GPS was not significantly associated with AUDsx at the baseline assessment or the rate of increase in AUDsx over time. Family history of alcohol problems was associated with more AUDsx at the beginning of college, but was not associated with rate of increase in AUDsx across college. Both peer deviance and interpersonal traumatic events were associated with more AUDsx; however, neither AD_GPS nor family history of alcohol problems moderated these associations. Findings indicate peer deviance and IPTE as salient risk factors for alcohol problems among African American college students. The null findings of AD_GPS and GXE effects suggest the need for larger sample sizes in gene discovery efforts to better characterize genetic risk for alcohol problems, particularly among populations of non-European ancestry. In the mean time, family history of alcohol problems remains to be a useful indicator of genetic risk for alcohol problems.

Authors

• Jinni Su, Virginia Commonwealth University
  Presenting Author

• Sally I-Chun Kuo, Virginia Commonwealth University
  Non-Presenting Author

• Jacquelyn L. Meyers, State University of New York Downstate Medical Center
  Non-Presenting Author

• Mignonne C. Guy, Virginia Commonwealth University
  Non-Presenting Author

• Danielle M. Dick, Virginia Commonwealth University
  Non-Presenting Author