In this study, we found that a polygenic risk score, created by using genetic variants from the STOMP meta-analysis, predicted the frequency of cigarettes smoked per day in a representative sample of African American adult residents of Detroit. In addition, we found that features of the neighborhood social and physical environments, including social cohesion and physical disorder, were associated with cigarette use in this population. Finally, we found the evidence of gene–environment interaction; the association between genetic risk and smoking was greater for individuals who had experienced trauma in their lifetimes and diminished for individuals who had increased social cohesion in their neighborhoods. These results agree with previous studies suggesting that riskier environments (for example, increased stressful life events and fewer social constraints) allow for an increased expression of genetic predispositions towards substance use.39 In using the aggregate measure of genetic risk, informed by the previous literature, we move gene–environment interaction studies forward by more accurately modeling the genetic architecture of cigarette smoking.
