the experimental arm of the study, as it may have been unsafe for them to abstain prior to the infusion sessions. As such, more severe alcohol dependent patients may have been excluded, thereby reducing sample variability and power to detect significant effects. It is also plausible that alcohol-specific effects were not detectable as a result of the modest main effect of alcohol (versus saline). Interestingly, the post-hoc test showing a trend towards greater tension reduction among more severely dependent patients is consistent with the neurobiological models predicting negative reinforcement as a primary motivational drive towards alcohol use at later stages of addiction (Koob, 2009; Koob and Le Moal, 2005). Likewise, albeit not alcohol-specific, higher levels of craving and sedation are also consistent with later stages of alcoholism. In sum, while the results of the secondary aim are far from conclusive, they represent a much needed step towards the translation of findings to clinical samples by hypothesis generation and testing that is informed by the neuroscience of addiction.
