Evidence That Implementation Intentions Enhance Cognitive Training and Reduce Alcohol Consumption in Heavy Drinkers: A Randomized Trial.

Abstract

Current training tasks to improve the cognitive deficits thought to be involved in sustained heavy drinking need further investigation to optimize their effectiveness. The present study investigated whether combining implementation intention provision with a cognitive training task had a measurable effect on alcohol consumption in heavy drinkers and explored the neural mechanisms underpinning any reductions in subsequent alcohol consumption. Thirty-two heavy-drinking participants completed approach-avoidance and visual probe training tasks preintervention and postintervention during functional Magnetic Resonance Imaging. Participants in the intervention group were randomized to form implementation intentions and participants in the control condition read a goal intention. Alcohol consumption was recorded preintervention and at 1 month follow-up. Compared to the control group, implementation intention provision significantly improved performance on alcohol-avoidance tasks postintervention, t(30) = -2.315, p = .028, d = .85, and reduced alcohol consumption by 6.9 units/week (1 unit = 10 mL or 8 g ethanol), F(1,30) = 4.263, p = .048 (d = .74), at follow-up. However, the analysis of functional Magnetic Resonance Imaging data revealed no significant differences between groups. These findings show for the first time that implementation intentions targeting cognitive processes can significantly reduce alcohol consumption among heavy drinkers. However, there was no evidence that the effects were mediated by changes in neural activity. Further work is required to explore the neural mechanisms underpinning the operation of implementation intentions. This trial was registered (ISRCTN:35503634) and is available at https://www.isrctn.com/ISRCTN35503634.