Working memory as a moderator of impulsivity and alcohol involvement: Testing the cognitive-motivational theory of alcohol use with prospective and working memory updating data

• Digit span moderated the relationship between social deviance and alcohol outcomes.
• The moderation effect persisted up to three years prospectively.
• This moderation effect was not found with measures of working memory updating.

Research consistently shows that individuals high in impulsivity are at increased risk for excessive alcohol use and alcohol-related problems including alcohol use disorders (AUDs). Recent theorizing posits that working memory (WM) ability might moderate this association, but extant studies have suffered from methodological shortcomings, particularly mischaracterizing WM as a single, unitary construct and using only cross-sectional designs. This paper reports two studies that attempted to replicate and extend previous investigations of the relationship between WM, impulsivity, and alcohol involvement using two independent samples. Study 1 used a large (N = 489 at baseline), prospective cohort of college students at high and low risk for AUD to investigate interactions between WM capacity and impulsivity on cross-sectional and prospective alcohol involvement. Study 2 used a large (N = 420), cross-sectional sample of participants in an alcohol challenge study to investigate similar interactions between WM updating and impulsivity on recent alcohol involvement. Whereas Study 1 found that WM capacity moderates the relationship between some measures of impulsivity and alcohol involvement, with effects prospectively predicting alcohol involvement for up to three years, Study 2 did not find similar moderation effects when using measures of WM updating. These findings highlight the multifaceted nature of WM, which is often overlooked in the alcohol and impulsivity literature.