Neighborhood density of alcohol outlets moderates genetic and environmental influences on alcohol problems

Background and Aims Geographic differences in rates of alcohol use disorder suggest that environmental factors and gene-environment interactions are likely to play an important role in its genesis. We aimed to examine whether living in a community with more alcohol outlets would facilitate the expression of the genetic propensity to develop alcohol problems. Design Cross-sectional twin/sibling study. Setting United States. Participants The participants were 18-26-year-old twin, full- and half-sibling pairs from Wave III of the National Longitudinal Study of Adolescent to Adult Health. Measurements Participants completed in-home interviews in which past year alcohol problems were assessed. Alcohol outlet densities were extracted from state-level liquor license databases aggregated at the census tract level. Findings There was evidence that estimates of genetic and environmental influences on alcohol problems varied as a function of the density of alcohol outlets in the community. The heritability of alcohol problems for those residing in a neighborhood with more than 10 on-premises outlets was 78% (95% confidence limits = 52-100%), compared with 11% (95% confidence limits = 0-29%) for those in a neighborhood with no on-premises outlets. This moderating effect of alcohol outlet density was not explained by state of residence, population density or neighborhood socio-demographic characteristics. Conclusions Individuals who are genetically predisposed to develop alcohol problems may be especially sensitive to the influence of many alcohol outlets in their community.