Prior studies of gene-environment interactions and alcohol-related problems have focused on participants of European descent. Less in known about how these factors interact in samples of African Americans. The current study tested genetic and environmental factors to uncover how they influence alcohol use disorder trajectories both independently and interactively. Environmental factors included peer deviance and interpersonal traumatic events. Genetic factors included family history and genome-wide polygenic use scores.
A sample of 1,119 college students with African ancestry (74% female) was identified from the Spit for Science (S4S) Study based on the availability of their alcohol use disorder symptoms data. The S4S tracks incoming university students longitudinally and includes saliva DNA samples for genotyping.
The genome-wide polygenic use score was selected as the genetic measure in this study because it gauges risk for alcohol use disorder based on many common genetic variants linked to alcohol dependence from across the genome. Alcohol use disorder symptoms were measured based on self-reported use behaviors anchored to DSM-5 criteria. Perceptions of peer deviance were assessed by participant reports of their friends’ alcohol and drug use, school and legal problems. An abbreviated Life Events Check-list was used to measure interpersonal traumatic events focused specifically on physical and sexual assault and unwanted sexual experiences. Family history was assessed by participant report of whether different family members had ever experienced problems with alcohol.
Results showed the genome-wide polygenic use scores did not predict trajectories of alcohol use disorder (AUD) symptoms. Family history was correlated with AUD symptoms, but only upon college entry. The rate of change in AUD symptoms across the college years was not correlated with family history. Both perceived peer deviance and interpersonal traumatic events were associated with increased AUD symptoms across time in college.
Future studies should use larger samples with more male participants to better understand how gene-environment interactions affect alcohol use disorders among students of African descent.
Take Away: Interpersonal traumatic events and peer deviance elevate risk for alcohol use disorder among African American college students. Family history and genetic factors studied did not predict trajectory of alcohol use disorder in this sample.