The effect of approach bias modification during alcohol withdrawal treatment on craving, and its relationship to post-treatment alcohol use in a randomised controlled trial

Background: Approach bias modification (ApBM) for alcohol use disorder helps prevent relapse, yet the psychological mechanisms underlying its efficacy remain unclear. Alcohol craving predicts relapse and appears to be related to the biased processing of alcohol stimuli which is reduced by ApBM. However, there is little research examining whether ApBM reduces alcohol craving. Methods: In a randomised controlled trial testing the effect of 4 ApBM sessions (vs. sham training) on post-treatment alcohol use in 300 alcohol withdrawal inpatients, we administered the Alcohol Craving Questionnaire – Short Form – Revised (ACQ-SF-R) pre and post-training and at 2-week, 3, 6 and 12-month follow ups; and a cue-induced craving measure pre and post training. Results: Groups did not significantly differ in terms of declines in ACQ-SF-R total scores (p = .712) or cue-induced craving (p = .841) between the first and last training session, nor in terms of ACQ-SF-R scores at follow-ups (p = .509). However, the ACQ-SF-R Expectancy subscale, which assesses craving based on anticipated positive reinforcement from alcohol, was significantly lower in the ApBM group than in controls following training (p = .030), although the group x time interaction for this subscale was non-significant (p = .062). Post-intervention Expectancy scores mediated only a small portion of ApBM's effect on post-discharge alcohol use (14% in intention-to-treat analysis, p = .046; 15% in per-protocol analysis, p = .020). Conclusions: ApBM does not appear to have robust, sustained effects on alcohol craving. Reduced craving is unlikely to account for ApBM's relapse prevention effects. However, further research on whether ApBM's effects are related to devaluation of alcohol reward expectancy is warranted. Trial registration: Australian New Zealand Clinical Trials Registry Identifier: ACTRN12617001241325