Predicting the development of complex genetically influenced disorders is complicated. Each condition (e.g., an alcohol use disorder [AUD]) is likely to encompass multiple phenotypes (e.g., for AUD: externalizing behaviors and a person’s alcohol response), each of which could explain part of the genetic contribution (e.g., Goldman et al., 2005; Reilly et al., 2017; Schuckit, 2014). Those phenotypes themselves are likely to reflect multiple genetically influenced sub-components that interrelate with the environment. The search for genes that underlie these complex genetically influenced conditions requires recognizing potential differences across phenotypes being studied. This critical review briefly addresses phenotypes related to how a person responds to alcohol, with an emphasis on specific gene variants potentially impacting alcohol sensitivity.
