F. Current models for the genetic architecture of human dependence on legal and illegal addictive substances in the population thus postulate that each is influenced roughly 50% by polygenic genetic influences, that is by variants in individual genes that each contribute modest amounts to this overall genetic vulnerability. These genetic architectural models posit that many of these genetic vulnerabilities increase risk for addcition to several pharmacologic classes of abused substances, but that some of these genetic influences are specific to drugs of one class [32].
