We selected genes in the dopamine pathways because multiple imaging studies have implicated dopamine-rich brain regions in experiments evoking cue-elicited craving for cocaine (Volkow et al., 2006; Childress et al., 1999) and other drugs (Kalivas & O’Brien, 2008; Kalivas & Volkow, 2005). This limbic activation suggests that genes in dopamine pathways might be of salience to craving but not all aspects of alcohol dependence. Despite the significant overlap between DSM-IV alcohol dependence and craving in our sample, we saw some support for differential effects of SNPs on craving, alcohol dependence and dependence without craving. We also found support for signals in SNCA, a gene previously implicated in a partially overlapping sample (Foroud et al., 2007). However, the SNPs identified from this study were not correlated with those identified by Foroud and colleagues.
