App-based contingency management to reduce heavy drinking days among smokers receiving varenicline: Feasibility, acceptability, and efficacy indicators from a phase I analog trial.

Tobacco and alcohol coaddiction is highly prevalent and represents a substantial challenge for treatment, as addiction to one of these substances leads to a worse prognosis when treating the other. In this pilot study, we evaluated the feasibility, acceptability, and signals of efficacy when incorporating varenicline (VC) and app-based contingency management (CM) to treat tobacco smoking and alcohol use disorders (AUD), concomitantly. Fourteen participants with an AUD who were seeking smoking cessation treatment were exposed to a within-subject A-B-A experimental design lasting 9 weeks. Participants were provided VC for smoking cessation throughout the study. Participants were also instructed to submit five daily breathalyzer samples using a mobile app. During the experimental phase (B), participants could earn reinforcers totaling $15 per day for submitting all breathalyzer samples with results below 0.08. Submitting all five samples on a given day occurred on 75% of study days, with VC adherence occurring on 74% of study days. Participants were retained for an average of 7.6 weeks and most of them (80%) found the app quick to learn and easy to use. A significant reduction of heavy-drinking days (p < .01) occurred during the B phase, and the number of daily cigarettes smoked significantly declined following each phase change (p < .01). The combination of VC and app-based CM was shown to be feasible and well accepted, with an initial signal of efficacy to reduce heavy-drinking and cigarette smoking. This combined therapeutic may provide a novel approach to treat tobacco smoking and AUD concomitantly. (PsycInfo Database Record (c) 2026 APA, all rights reserved).