Several lines of animal and human research have linked the GABAergic neurotransmitter system to various aspects of addictive behaviors and pharmacotherapies (Ikemoto, 2005; Kalivas, 2007; Koob, 2004; Roberts, 2005). The GAD genes are of special interests because GAD is the rate-limiting enzyme for synthesis of GABA in the brain. Animal QTL studies of alcohol-related phenotypes have consistently identified murine genomic regions which mapped to GABA receptor and the GAD genes (Buck and Finn, 2001; Crabbe et al., 1999, 2006). Past rodent studies have also produced valuable information for understanding genetic effects on specific components of alcohol-related phenotypes relative to the heterogeneous performance of AD clinical diagnosis in humans. The present study examined the association between GAD genes with AD as well as relevant alcohol-related phenotypes in humans.
