Differentiating the Contribution of Pharmacological from Alcohol Expectancy Effects to Changes in Subjective Response and Priming Over Successive Drinks

Background Alcohol consumption can prime motivation to continue drinking and may contribute to excessive drinking. Most alcohol administration research assesses the effect of a single alcohol dose on outcome measures; however, this differs from typical drinking occasions in which several drinks are consumed over time. This research tracks priming measures (alcohol urge, latency to first sip, and consumption time) and subjective effects (intoxication, stimulation, and sedation) across consumption of 5 drinks, over a period of 2.5hours. Alcohol, placebo, and no-alcohol (i.e., soft drink) conditions are compared with isolate the effects of alcohol expectancies and differentiate these from alcohol's pharmacological effects. Methods Alcohol urge and subjective state were measured before and after an initial drink was consumed (preload: alcohol, placebo, or no-alcohol). Four additional drinking phases followed whereby participants had access to 2 drinks (alcohol/no-alcohol, or placebo/no-alcohol). Experimental priming (urge, latency to first sip, consumption time) and subjective effect (intoxication, stimulation, and sedation) outcomes were recorded after each drink. Results The pattern of alcohol urge following placebo drinks differed compared with alcohol and no-alcohol consumption, Fs(1, 90)>4.10, ps