Human studies investigating the OPRM1 polymorphism have suggested acrucial role of this single nucleotide polymorphism (SNP) in AD, treatment responseand automatic approach biases to conditioned cues (Chamorro et al., 2012; Filbey et al., 2008; Ray and Hutchison, 2004; Wiers et al., 2009). The gene discussed is OPRM1; the disease is Alzheimer disease.