Genetic factors are responsible for around 50% of individual differences in likelihood of developing alcohol use disorder (AUD). Interpersonal factors and psychiatric disorders have also beencorrelated with alcohol use/misuse. Endophenotypes are described as the mediational pathways between genes and behavior. Drinking motives may be one potential endophenotype for alcohol misuse. Many drinking motives exist including coping, enhancement, social, and cultural. This study examines the genetic and environmental etiology of drinking motives and their potential utility as endophenotypes.
The study’s sample consisted of 9,889 college students who participated in the “Spit for Science” study. Participants completed an online survey that assessed the following drinking motives: coping, enhancement, conformity, and social. Alcohol use behaviors, symptoms of AUD, and environmental risk and protective factors (parenting behaviors, peer deviance, and exposure to traumatic events) were also assessed. Lastly, genotyping was completed. Data was analyzed using Pearson correlations, linear regression analyzes, and genome-wide associations (GWAS).
Results of the data analysis showed male gender, older age, and recent trauma exposure were associated with higher levels of conformity motives. Parental autonomy was correlated with lower levels of all drinking motives while high parental involvement was correlated with social and enhancement motives. Peer deviance was also associated with higher levels of all motives except conformity. GWAS indicated 16-22% single nucleotide (SNP) heritability estimates for positive reinforcement motives and 14-16% for negative reinforcement motives. There were also suggestive associations between the SIRT4 gene and conformity motives and the PERC gene and enhancement motives. Lastly, Bonferroni correlations indicated a significant genetic correlation between coping motives and AUD diagnoses but not alcohol consumption.
Takeaway: Drinking motives could serve as a potential endophenotype for alcohol misuse among college students.