The rapid progression of genetic research is uniting two areas of investigation that each face significant challenges in their own right: substance-use disorders and psychiatric genetics. Research on the genetics of alcohol and drug dependence offers great promise for improving our understanding of these disorders and developing new therapies, but this line of research also requires careful consideration from an ethical standpoint. In this chapter, we discuss the potential ethical challenges arising from the genetics of substance-use disorders, ranging from concrete risks that could stem from research participation to more abstract considerations related to the social and legal implications of this work.

Introduction: Promises

Genetic factors have long been known to be important for the development of substance-use disorders, as established by traditional genetic epidemiology methods such as twin, family, and adoption studies (Gelernter and Kranzler, 2009: 91–99; Gelernter and Kranzler, 2010: 77–84). Heritability estimates for nicotine, alcohol, and drug addiction generally fall in the range of 50 to 60% (Bierut, 2011: 618–627). The popular understanding of this genetic risk, however, is commonly clouded by inaccurate “folk genetic” concepts, e.g., the quasi-Mendelian idea that there could exist a “gene for” alcoholism or drug dependence. In fact, despite recent advances in the field, a significant fraction of the variance of genetic influences on substance-use disorders remains unexplained; clearly, these disorders are polygenic and develop in response to a complex set of variables (Frazer et al., 2009: 241–251). With that said, research on the genetics of alcohol and drug dependence does carry several important promises.