Recent evidence based on the COGA study indicates that the CHRM2 gene also is associated with a diagnosis of alcohol dependence and depression (Wang et al. 2004), comorbid alcohol and drug dependence (which reflects a more severe addiction profile) (Dick et al. 2007), and a spectrum of externalizing disorders (Dick et al. 2008). These findings have been replicated by other groups (Comings et al. 2002; Luo et al. 2005). Together, these results indicate that genes important for the expression of the endophenotype of brain oscillations can help researchers identify genes that increase the susceptibility for alcohol dependence and related disorders.
