Neuromodulation techniques for the treatment of nicotine addiction

Nicotine addiction remains one of the most widespread substance use disorders and a major public health concern. Despite available treatments, long-term cessation rates are modest, underscoring the need for more effective approaches. Non-invasive brain stimulation (NIBS) has emerged as a promising strategy to modulate neural circuits involved in craving, reward, and cognitive control. This study evaluated a novel combined neuromodulation protocol integrating transcranial direct current stimulation (tDCS) with repetitive transcranial magnetic stimulation (rTMS). The approach leverages the priming effect of anodal tDCS to enhance cortical excitability and potentiate the subsequent effects of rTMS over the dorsolateral prefrontal cortex (DLPFC), a region central to executive control and addiction. Seventy-two adult smokers were randomly assigned to either a standard rTMS protocol (21 daily sessions) or an intensive combined protocol consisting of sequential tDCS and rTMS administered twice daily for five days. Outcomes included cigarette consumption, nicotine dependence (Fagerström Test), abstinence rates, and resting motor threshold as a measure of cortical excitability. The combined protocol led to significantly greater reductions in cigarette use and dependence compared to standard rTMS. Participants in this group were more likely to achieve ≥50% reductions in smoking and higher short-term abstinence rates. The intervention also showed better feasibility, with lower dropout rates. Both treatments reduced motor threshold, indicating increased cortical excitability and neuroplastic changes. These findings suggest that sequential tDCS–rTMS is an effective and time-efficient approach for targeting neural mechanisms underlying nicotine dependence. By enhancing prefrontal plasticity, it may offer clinical advantages over single-modality treatments. Future research using advanced techniques such as TMS-EEG could help identify biomarkers of response and guide personalized neuromodulation strategies in addiction treatment.