Indeed, AD individuals have reduced volume and cortical thickness of the orbitofrontal cortex (Durazzo et al.2011) that predicts future relapse (Beck et al.2012) and simultaneously show heightened drug cue reactivity in this region (Chase et al.2011; Kuhn & Gallinat 2011; Engelmann et al.2012), which is modulated by gene type during naltrexone (OPRM1 gene G allele carriers) (Kareken et al.2010). This evidence concerns the gene OPRM1 and Alzheimer disease.