Transcranial direct current stimulation, implicit alcohol associations and craving

Abstract

Previous research has shown that stimulation of the left dorsolateral prefrontal cortex (DLPFC) enhances working memory (e.g. in the n-back task), and reduces craving for cigarettes and alcohol. Stimulation of the right inferior frontal gyrus (IFG) improves response inhibition. The underlying mechanisms are not clearly understood, nor is it known whether IFG stimulation also reduces craving. Here, we compared effects of DLPFC, IFG, and sham stimulation on craving in heavy drinkers in a small sample (n=41). We also tested effects of tDCS on overcoming response biases due to associations between alcohol and valence and alcohol and approach, using implicit association tests (IATs). Mild craving was reduced after DLPFC stimulation. Categorization of valence attribute words in the IAT was faster after DLPFC stimulation. We conclude that DLPFC stimulation can reduce craving in heavy drinkers, but found no evidence for tDCS induced changes in alcohol biases, although low power necessitates caution.

Transcranial Direct Current Stimulation: a potential novel treatment for alcohol addiction and abuse

“…It is also possible that tDCS may exert its influence on drug-related cues and craving by modulating the adjoining areas of DLPFC such as OFC 29,30 that have connections to subcortical regions 31 . However in den Uyl TEet al study 21 , anodal stimulation of right IFG failed to show significant decrease in craving (alcohol) despite showing increase in response inhibition in an earlier study 32 …”

“…This is supported by the study which show decrease attention to substance abuse related cues 34 . Again, in den Uyl TE et al study 21 such an effect was not seen.…”

“…Hence, craving to drugs may increase the activity in DLPFC through mesolimbic pathway 25 . Three studies were done to measure the effect on craving using anode placed over left DLPFC [17][18][19][20][21] . In only one study, right DLPFC anodal was also used 17 .…”

“…The effects of tDCS have been shown to last for some time -30-120 mins 13 even after the end of stimulation period 11,12 tDCS has been shown to be effective in ameliorating the signs and symptoms of various psychiatric disorders including major depressive disorder, schizophrenia, obsessive-compulsive disorder 14,15,16 . Very recently, interest has arisen in the potential effect of tDCSon addiction as it has also shown to be effective in reducing craving and relapse rate in people with alcoholic problems [17][18][19][20][21] . In this article, we would review studies done using tDCS in people with AUD.…”

“…No significant correlation was seen between bias scores and AUDIT, alcohol time line follow back (TLFB) or alcohol approach and avoidance questionnaire (AAAQ) Inclined scores. The lack of significant effect on bias scores may be due to inclusion of only heavy drinkers or lack of power 21 .…”