Sequential dual-target tDCS for tobacco use disorder: A longitudinal pilot case series targeting craving and inhibitory control

BACKGROUND: Transcranial direct current stimulation (tDCS) is increasingly explored as an adjunctive intervention for Tobacco Use Disorder (TUD). Studies typically employ single-site stimulation protocols, and reported effects on craving and relapse have varied. OBJECTIVE: To examine whether sequential dual-target tDCS could influence smoking behavior and relapse-relevant mechanisms in TUD. METHODS: In this case series, three adults with TUD underwent a two-week sequential tDCS protocol targeting the left dorsolateral prefrontal cortex and pre-supplementary motor area. Assessments were conducted at baseline, post-intervention, and at 1- and 6-month follow-up characterize clinical, biological, and cognitive trajectories over time. RESULTS: All cases showed reductions in cigarette consumption across the six-month follow-up, accompanied by decreases in biochemical exposure markers. Trajectories were heterogeneous across participants. Two individuals achieved abstinence at follow-up, while one maintained sustained reduction. Craving and withdrawal symptoms declined, and inhibitory control improved alongside reductions in exposure markers. The nicotine metabolite ratio remained stable across assessments, consistent with its role as an index of metabolic phenotype. CONCLUSIONS: Sequential dual-target tDCS was associated with longitudinal improvements in smoking behavior and relapse-related clinical and cognitive markers. These findings support further investigation of dual-target neuromodulation as a potential adjunctive strategy for smoking cessation.