(EEG beta activity) that characterizes individuals at risk for alcoholism in the COGA study (Porjesz et al., 2002), heavy drinking in the Framingham study (Wyszynski et al., 2003), cannabis dependence in the nicotine addiction genetics project (Agrawal et al., 2008), and haplotypes of “addiction phenotypes” in substance abusers (Drgon et al., 2006). Additional sites in the genome where there have been duplications of findings for linkage to alcohol and other substance dependence phenotypes within a broad support interval can be found on chromosome 2 (Reich et al., 1998; Dick et al., 2004; Ehlers et al., 2008), chromosome 5 (Hill et al., 2004; Ehlers and Wilhelmsen, 2005; Gelernter et al., 2006), chromosome 6 (Cantor and Lanning, 1999; Hill et al., 2004; Swan et al., 2006; Ehlers and Wilhelmsen, 2007), chromosome 15 (Dick et al., 2002; Ehlers et al., 2004), and chromosome 16 (Foroud et al., 1998, Ehlers et al., 2004). Strong evidence for a site on chromosome 7 has also been found by the COGA study; however, it has not as yet been duplicated by other studies (see Saccone et al., 2005; Dick et al., 2008).
