Sweet Liking Phenotype, Alcohol Craving and Response to Naltrexone Treatment in Alcohol Dependence

Aims: To investigate the relationship between the sweet liking/sweet disliking phenotype (a putative probe of brain opioid function), craving for alcohol and response to treatment with naltrexone in individuals with alcohol dependence. Methods: Forty individuals with alcohol dependence were enrolled in a 12-week open-label study of 50 mg of naltrexone with four sessions of motivational enhancement therapy. Prior to treatment, individuals completed a sweet preference test and the Penn Alcohol Craving Scale. Subjects were categorized as sweet liking (SL), n = 15, or sweet disliking (SDL), n = 25, via a standard sweet tasting paradigm. The sweet tasting results were blinded to the subjects and to treatment staff. SL status, pretreatment craving and their interaction were examined as predictors of frequency of abstinent days and heavy drinking days during treatment with naltrexone. Results: SL and SDL subjects achieved similar reductions in percent heavy drinking days with treatment. During treatment, SDL subjects had 48% abstinent days compared to 30% for SL subjects (P = 0.034). Pretreatment craving did not predict % heavy drinking days or % abstinent days. An interaction effect was found between the SL/SDL phenotype and pretreatment craving such that SL subjects with high craving demonstrated higher rates of percent abstinent days whereas SDL subjects with high craving demonstrated lower rates of percent abstinent days, P < 0.001. Conclusions: These findings indicate that the SL/SDL phenotype may predict variation in response to naltrexone and/or counseling treatment. Furthermore, the SL/SDL phenotype may interact with craving to provide a more robust prediction of outcome with naltrexone or counseling