The role of neuropsychological mechanisms in implementation intentions to reduce alcohol consumption among heavy drinkers: a randomized trial

Elly Mcgrath,Christopher J Armitage,Rebecca Elliott,Tim Millar

doi:10.1007/s10865-019-00078-5

Abstract

Implementation intention formation, which involves identifying triggers and linking them with coping strategies, has proven effective at reducing alcohol consumption in general populations. For the first time, the present study tested the ability of implementation intentions to reduce alcohol consumption among heavy drinkers and to explore potential neuropsychological mechanisms. At baseline, participants were randomized to form implementation intentions or to an active control group. There was a 5.7 unit (1 unit = 10 ml or 8 g ethanol) per week reduction ([95%CI 0.15, 11.19], p = 0.048) in alcohol consumption at 1 month follow-up among participants who formed implementation intentions, which was significantly more than controls F(1, 91) = 3.95, p = 0.048, a medium effect size (d = 0.47, Cohen, 1992). No significant differences in performance on the neuropsychological tasks were found between groups. The present study demonstrates for the first time that implementation intentions reduce alcohol consumption among heavy drinkers.

Highlights

It is estimated that 31% of men and 16% of women drink in excess of UK Government guidelines (Office for National Statistics, 2016) and research suggests that excessive drinkers want to decrease their drinking but show a lack of engagement with formal interventions that are often face to face and can last several weeks (Aalto et al, 2001; Murgraff et al, 2006)
In terms of reducing alcohol consumption, similar effect sizes from implementation intention-based interventions have been found in general populations (Armitage, 2009, d = 0.67; Hagger et al, 2012, d = 0.55; Murgraff et al, 2006, d = 0.68), but not yet among heavy drinkers
Implementation intentions are hypothesised to bring about behaviour change through changes in cognition, but currently there is no research that has examined the ability of implementation intentions to compensate for the cognitive deficits associated with excessive alcohol use (Field & Cox, 2008)

Summary

Introduction

It is estimated that 31% of men and 16% of women drink in excess of UK Government guidelines (Office for National Statistics, 2016) and research suggests that excessive drinkers want to decrease their drinking but show a lack of engagement with formal interventions that are often face to face and can last several weeks (Aalto et al, 2001; Murgraff et al, 2006). Implementation intentions have been shown to improve bottom-up control over action (Gollwitzer & Sheeran, 2006) and so implementation intentions should: (a) improve deficits in executive functioning that are associated with weaker links between intention to change and poorer planning skills (Mullan et al, 2011) by providing specific and tailored plans; (b) reduce impulsivity by promoting healthier choices, which allows inhibition of unhelpful responses (Gollwitzer & Sheeran, 2006; Parks-Stamm et al, 2007); and (c) highlight attentional bias by identifying a critical cue or situation that is commonly linked to the unhealthy behaviour the user would like to change (Achtziger et al, 2012). Evidence in support of the full causal pathway has proven elusive, with many studies testing whether implementation intentions improve cognitive performance or behaviour, but rarely testing whether improvements in cognitive performance caused by implementation intentions subsequently change behaviour (Gollwitzer & Sheeran, 2006; but see Armitage, 2016)

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