Modulation of smoking and decision-making behaviors with transcranial direct current stimulation in tobacco smokers: A preliminary study

Abstract

Background Most tobacco smokers who wish to quit fail to reach their goal. One important, insufficiently emphasized aspect of addiction relates to the decision-making system, often characterized by dysfunctional cognitive control and a powerful drive for reward. Recent proof-of-principle studies indicate that transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) can transiently modulate processes involved in decision-making, and reduce substance intake and craving for various addictions. We previously proposed that this beneficial effect of stimulation for reducing addictive behaviors is in part mediated by more reflective decision-making. The goal of this study was to test whether nicotine intake and decision-making behaviors are modulated by tDCS over the DLPFC in tobacco smokers who wished to quit smoking. Methods Subjects received two five-day tDCS regimens (active or sham). Stimulation was delivered over the right DLPFC at a 2mA during 30 minutes. Nicotine cravings, cigarette consumption and decision-making were assessed before and after each session. Results Main findings include a significant decrease in the number of cigarettes smoked when participants received active as compared to sham stimulation. This effect lasted up to four days after the end of the stimulation regimen. In regards to decision-making, smokers rejected more often offers of cigarettes, but not offers of money, after they received active as compared to sham stimulation at the Ultimatum Game. No significant change was observed at the Risk Task with cigarettes or money as rewards. Conclusion Overall, these findings suggest that tDCS over the DLPFC may be beneficial for smoking reduction and induce reward sensitive effects.

Non-invasive Brain Stimulation for the Treatment of Nicotine Addiction: Potential and Challenges

“…Two studies [23,24] used an electrode protocol with the anode on the left dlPFC and the cathode on the right dlPFC. In contrast, using the reversed placement of electrodes, a study [25] also reported positive tDCS effects on smoking-related behaviors.…”

“…In another study, Fecteau et al attempted to modulate the decisionmaking behavior of smokers via stimulation over the same cortical region. They showed not only a four-day decrease in the number of cigarettes consumed after anodal stimulation but also more rejections of cigarettes but not monetary offers in an Ultimatum Game [25]. Besides the dlPFC, the fronto-parieto-temporal association area has also been proposed as an accessible stimulation site for modulating smoking-related behaviors [26].…”

The modulating effects of brain stimulation on emotion regulation and decision-making

“…For addiction studies using tDCS modulation, cigarette consumption was measured for two five-day tDCS applications (active or sham). In smokers, active tDCS (right anodal/left cathodal tDCS to the DLPFC) significantly decreased the number of cigarettes smoked compared to sham stimulation and the effects were maintained for 4 days [17]. Boggio et al [6] applied tDCS to the DLPFC (left anodal/right cathodal tDCS, right anodal/left cathodal tDCS, or sham tDCS) to chronic marijuana users in their study.…”

“…In summary, tDCS influences and modulates risk-taking behaviors [5,12,18,19,47,82,83], choice modulation [46], delayed discounting [30], maladaptive decisionmaking [81], probabilistic guessing [29], moral judgment [37], sunk-cost effect [4], exploration-exploitation trade-offs [61], decision-making and cognitive impulse control [42], perception of space and time [79], dual-task performance [22], model-based learning [70], addiction [6,17,26,60,80], food craving [23,35], and perceptual decision-making [34].…”

Transcranial direct current stimulation in psychiatric disorders

“…They applied anodal tDCS to the left dorsolateral prefrontal cortex and cathode to the right supra-orbital area for 20 min with a current intensity of 2.0 mA [116] . Fecteau et al [117] rated two five-day tDCS regimens (active or sham). Stimulation was delivered over the right DLPFC at a 2 mA during 30 min in twelve adults.…”