Other studies have revealed further complexity in the relationship between GABRA2 and AD risk where GABRA2 modulates risk for other co-occurring psychiatric disorders including conduct disorder (Dick et al., 2006) and anxiety (Enoch et al., 2006) and the presence of comorbidity within AD samples has been shown to affect the likelihood of observing an association between GABRA2 and AD. However, the interaction can result in conflicting findings. While Covault and colleagues (2004) observed stronger association with AD in a restricted sample of alcoholics without comorbid major depression, Matthews et al. (2007) found no evidence of association between GABRA2 and AD in alcoholic subjects selected for minimal primary comorbidity for drug dependence and other psychiatric disorders.
