Gene by social-environment interaction for substance abuse: A pilot study in the Chinese population

Background: While previous sociological and addiction literatures have shown the significant effects of social strain and social support on addictive behaviors among the Chinese, relatively little is known about the role of genetic factors in addiction among the Chinese. Guided by the differential susceptibility to context model, this study examines how strain and social support interact with genetic factors in predicting substance abuse, including smoking, alcohol abuse and illicit drug use, in the Chinese population. As a recently developed framework, the model of differential susceptibility to context posits that some individuals are genetically predisposed to be more susceptible than others to a range of social contextual influence, whether that social environment is adverse or supportive.
Methods: The sample included 383 young male adults in Hong Kong and 421 young male adults in Guangzhou, mainland China. We conducted a community-based survey of the male participants, and collected their saliva samples to extract their DNA. We used PLINK 1.90 beta and GCTA 1.26.0 to examine the genetic association with substance abuse and the interaction effects between genotypes and social variables.
Findings: While certain genotypes have direct effects on the substance abuse outcomes, their effects on addiction are also moderated by stress in the childhood, social strain, family support, and community support.
Discussion: Incorporating genetic information into the study of health risk behaviors and investigating the interaction between genes and environment will provide a more insightful prediction of the circumstances under which the social contextual variables increase or decrease health risks.