Effect of transcranial direct current stimulation on tobacco consumption: A randomized placebo-controlled trial

Abstract

Craving is the main factor of smoking relapse. Smoking withdrawal treatments are inefficient on this one. Neurophysiological studies have provided evidence in the understanding of craving. It involves surface structures including the dorsolateral prefrontal cortex (DLPFC). Transcranial direct current stimulation (tDCS) of the DLPFC reduces smoking cue-induced craving (Fregni F et al J Clin Psychiatry. 2008; 69(1):32-40). The aim of the study was to assess the effects of repeated tDCS sessions on tobacco consumption. In Toulouse hospital between July 2013 and January 2014, thirty-four dependent smokers were randomized to receive anodal (two milliamps) or sham tDCS on the left DLPFC for five consecutive days. Using repeated mesures analyses of variance (ANOVA), the primary outcome measure was the change of salivary cotinine rate between the first and the fifth day of stimulation. All patients tolerated tDCS without complications. In the group of active stimulation, our results show that the reduction of salivary cotinine rate and secondary outcome measures (exhaled carbon monoxide (CO), number of cigarettes smoked per day, level of craving) were not significant compared with sham tDCS group. However, among heavy smokers (over twenty cigarettes per day), the level of exhaled CO decreased significantly in the active tDCS group ( F = 5.10, p = 0.01) at the fifth day and ten days after the end of stimulation ( post hoc : p = 0.04 and p