ABSTRACT
Other Gene-Targeted Expression Studies ........................ 461 30.3 Human Studies ............................................................................................. 462
30.3.1 Twin and Adoption Studies ............................................................. 462 30.3.2 Candidate Gene Studies ................................................................... 463 30.3.3 Identification of Risk Markers and QTLs ....................................... 463
30.4 Gene Expression Analyses........................................................................... 464 30.5 Conclusions .................................................................................................. 464 Acknowledgments.................................................................................................. 464 References.............................................................................................................. 464
Of all drugs of abuse studied to determine genetic contributions to susceptibility to their effects, alcohol has been by far the most frequent focus. Both animal model and human genetic studies will be mentioned here. A historically rich literature with genetic animal models has explored the general contribution of genetics to alcohol responsiveness, and has been helpful in elucidating the drug’s mechanism of action on the nervous system. Some studies using genetic animal models have attempted to identify specific genes that increase or decrease responsiveness for a number of alcohol’s effects. Most human studies have been of alcoholics and their relatives, and have compared relative risks for alcohol dependence disorders in twins, adoptees, or other relatives. More recently, human studies have also addressed the goal of identifying individual genes that might contribute to alcoholism risk, or to individual differences in endophenotypes, which also are associated with alcoholism risk.
