is the basis of much of the contemporary effort in the field of pharmacogenetics (Evans and Relling, 1999). Thus, a critical question remains: for which patients will pharmacotherapy have the greatest benefit? For naltrexone, there are two studies suggesting specific genotypes of the mu-opioid receptor may be associated with greater treatment response (Oslin et al., 2003; Anton et al., 2008). In these two studies about a quarter of individuals had a polymorphism that predicted a robust naltrexone treatment response. These treatment results, combined with human laboratory data showing an association between the genotype and alcohol cue response, justify conducting a daily diary study in individuals treated with naltrexone and genotyped while in a residential setting where alcohol use and cues may be limited (Ray and Hutchison, 2004). This type of experiment would provide a further understanding of alcohol craving classes and further justification for craving being an endophenotype.
