Effects of electrical neuromodulation on Craving, Relapse and Cognitive Functions among Patients with Cocaine Use Disorder: A Multi-Session tDCS Study v2

Background: The use of transcranial Direct Current Stimulation (tDCS) has previously shown promising results for reducing craving in cocaine use disorder. In this study we assessed therapeutic and behavioural effects of multi-session tDCS to further explore the potential of tDCS as add-on intervention in the treatment of cocaine use disorder. Methods: In a randomized, placebo-controlled, between subject study, we applied tDCS bilaterally with the anodal electrode targeting the right DLPFC (https://clinicaltrials.gov/ct2/show/NCT03025321). Patients with cocaine use disorder were allocated to ten sessions of either active tDCS (n = 29) or sham tDCS (n = 30) on five consecutive days. Inhibitory control and risky decision-making were measured via a Go-NoGo task and a two-choice gambling task, respectively, each at baseline, one day after all tDCS sessions and a follow up after three months. In addition, relapse at follow-up and craving were measured. Results: There was no significant effect of active tDCS on the number of relapse days and craving. Relapse was frequent among patients who had received either active or sham tDCS (48.0% and 69.2%, respectively), despite an overall decrease in craving during the first two weeks of treatment. An additional analysis revealed that active tDCS significantly reduced relapse rates for crack cocaine use only (n = 36). No effects were found on cognitive functions. Conclusion: Although somewhat promising results were obtained regarding relapse among cocaine users, we believe that further research is required to consolidate the use of tDCS as a complementary treatment in cocaine use disorder.