reduces the number of drinking days (O’Malley et al., 1992, Volpicelli et al., 1992) and the number of drinks per drinking episode (Chick et al., 2000, Guardia et al., 2002, Morris et al., 2001, O’Malley et al., 1992). Results from the COMBINE Study, a large multi-site controlled trial, found that naltrexone was an effective treatment for alcohol dependence when delivered in combination with a medically-oriented behavioral intervention (Anton et al., 2006). A few studies however, have not found support for the efficacy of naltrexone (Killeen et al., 2004, Kranzler et al., 2000, Krystal et al., 2001).