Effects of repeated transcranial direct current stimulation on smoking, craving and brain reactivity to smoking cues

Recent studies have shown that transcranial direct current stimulation (tDCS) may reduce craving and smoking. However, little is known regarding brain correlates of these behavioral changes. We aimed to evaluate whether 10 sessions of tDCS modulate cigarette consumption, craving and brain reactivity to smoking cues in subjects with tobacco use disorder (TUD). In a double blind parallel-arms study, 29 subjects with TUD who wished to quit smoking were randomly assigned to receive 10 sessions of either active or sham tDCS applied with the anode over the right dorsolateral prefrontal cortex (DLPFC) and a large cathode over the left occipital region. As compared to sham, active tDCS significantly reduced smoking craving and increased brain reactivity to smoking-cues within the right posterior cingulate, as measured with a functional magnetic resonance imaging event-related paradigm. However, we failed to find a significant difference between active and sham groups regarding the self-reported number of cigarettes smoked and the exhaled carbon monoxide during one month. These findings suggested that 10 sessions of tDCS over the right DLPFC may reduce craving by modulating activity within the resisting-to-smoke network but might not be significantly more effective than sham to decrease cigarette consumption.