Background & Aims
An initial dose of alcohol can motivate – or prime – further drinking and may precipitate (re)lapse and bingeing. Lab-based studies have investigated the alcohol priming effect; however, heterogeneity in designs has resulted in some inconsistent findings. The aims of this meta-analysis were to i) determine the pooled effect size for motivation to drink following priming, measured by alcohol consumption and craving, and ii) examine whether design characteristics influenced any priming effect.
Literature searches of PsycINFO, PubMed and Scopus in October 2020 (updated October 2021) identified lab-based alcohol priming studies which assessed effect of priming on motivation to drink. A tailored risk-of-bias tool assessed quality of lab-based studies. Random effects meta-analyses were computed on outcome data from 38 studies comparing the effect of a priming dose of alcohol against control on subsequent alcohol consumption/self-reported craving. Study characteristics that might have affected outcomes were design type (within/between-participant), dose of prime, time of motivation assessment, type of control drink (placebo alcohol/soft drink).
Relative to control, alcohol had a small-to-moderate priming effect on subsequent alcohol consumption (standardised mean difference [SMD] = .336 [95% confidence interval [CI]: .171, .500) and craving (SMD = .431 [95% CI: .306, .555]). Aspects of study design differentially affected consumption and craving. The size of the priming dose had no effect on consumption, but larger doses were sometimes associated with greater craving (with craving generally following the blood alcohol curve). Alcohol priming effects for consumption, but not craving, were smaller when compared with placebo, relative to soft drink, control.
Lab-based alcohol priming studies are a valid paradigm from which to investigate the impact of acute intoxication on alcohol motivation. Designs are needed which assess the impact of acute consumption on motivation to drink in more varied and realistic ways.