LAUSR

AIMS For the first time in a clinical sample with alcohol use disorder (AUD), this study compared the effects of two versions of alcohol-specific inhibition training (Alc-IT) on drinking outcomes and on experimental parameters assessing two possible working mechanisms: stimulus devaluation and inhibitory enhancement. DESIGN Multicentre, double-blind, three-arm, clinical RCT with 3-, 6- and 12-month follow-up comparing standard Alc-IT, improved Alc-IT, and an active control condition. SETTING Three specialized AUD treatment centres in Switzerland. PARTICIPANTS N = 242 detoxified, recently abstinent patients with severe AUD (18-60 years; 29.8% female). Intervention and Comparator Both interventions (standard Alc-IT (n=84), improved Alc-IT (n=79)) and the comparator (unspecific inhibition training (n=79)) consisted of six sessions of a modified inhibitory task (Go-NoGo-task) with alcohol-related and neutral stimuli. Both versions of Alc-IT required response inhibition in alcohol-related trials but differed in Go/NoGo-ratios (standard: 50/50; improved: 75/25), with improved Alc-IT posing higher inhibitory demands. The control condition, an unspecific inhibition training, featured alcohol-related pictures in Go- as well as NoGo-trials. MEASUREMENTS The primary outcome, percentage of days abstinent, was assessed at 3-month follow-up with a timeline follow-back interview. FINDINGS The group receiving improved Alc-IT showed a significantly higher percentage of days abstinent at 3-month follow-up compared with the control group (γcontrol = 74.30 ; γimproved = 85.78 ; β = 11.48, 95% confidence interval (CI) [2.57, 20.40] p = .012, adjusted r2 = .062), while for standard Alc-IT no effect significantly different from zero was detected (γstandard = 70.95 ; β = -3.35 , 95%-CI [-12.20, 5.50], p = .457, adjusted r2 = -.04). CONCLUSIONS Alcohol-specific inhibition training with high inhibitory demands increased days abstinent at 3-month follow-up in patients with severe alcohol use disorder. Such an improved, inhibitory-demanding, alcohol-specific inhibition training outperformed the standard version of alcohol-specific inhibition training, suggesting an inhibitory working mechanism.