Aims: Investigate the roles of pharmacology and expectancy in the effects of alcohol and determine whether findings are influenced by binge drinking.
Design: A within-subjects balanced placebo design. Participants completed four conditions: Told alcohol/Give alcohol; Told alcohol/Given placebo; Told soft/Given soft drink, Told soft/Given alcohol.
Setting: St George’s, University of London.
Participants: Sixteen (8 bingers, 8 non-bingers)
Measurements: The Alcohol Expectancy Questionnaire (AEQ) and the Temptation & Restraint Inventory (TRI) assessed participant’s alcohol expectancies and cognitions. Mood was measured using a visual analogue scale.
Following drinks and a 20-minute rest, participants completed the Immediate and Delayed Memory Task (IMT/DMT) to assess attention and memory and the Go-stop Paradigm (GSP) to assess impulsivity (order counterbalanced).
Findings: Bingers reported: preoccupation with alcohol (p=0.01); impaired intake control (p=0.01); drinking in response to negative affect (p<0.01); reinforcing alcohol expectations (p≤0.04).
Although alcohol consumption increased lightheadedness (p<0.001), this finding was exacerbated in bingers when instructed alcohol (interaction: p=0.04).
Alcohol consumption (men: 0.6g/kg, women: 0.5g/kg) decreased correct responding on the IMT (p=0.011).
Bingers made more errors on the DMT when instructed alcohol, irrespective of content. The opposite pattern was found for non-bingers (interaction: p=0.03).
Behavioural inhibition on the GSP was greatest in the told alcohol/given soft drink condition (p<0.01) and bingers made most errors (p=0.04).
Conclusion: Bingers report alcohol-related cognitions and expectancies linked with risk of alcohol dependence. Although alcohol consumption had some effect on measures, expectations were more influential. Alcohol instruction led to performance impairment in bingers but some improvement in non-bingers. Non-bingers may recognise alcohol’s potential impairing effects but engage in compensatory behaviour. Such findings may be used to challenge binge drinker expectations and reduce the aversive effects of alcohol.