Association strategies in substance abuse.

Classical genetic studies now provide fairly strong support to the idea that polygenic influences contribute to interindividual differences in vulnerability to drug abuse and dependence. Molecular genetic association studies have identified the D2 dopamine receptor gene as a candidate to contribute some of this genetic influence, although several cautions in utilizing association approaches must be recognized in interpreting their data. Clinical features of drug abuse that make association studies likely to play increasingly large roles in elucidating its underlying molecular genetics are discussed.