Efficacy and safety of transcranial direct current stimulation in alcohol use disorder: A randomized controlled...

Current treatment options for alcohol use disorder are limited. Transcranial direct current stimulation has been proposed as a therapeutic approach, but evidence remains scarce. This study aimed to compare active vs. sham transcranial direct current stimulation to evaluate its efficacy and safety in reducing alcohol consumption in a large sample of individuals with alcohol use disorder.

REDSTIM is a triple-blind, randomized, sham-controlled trial that was conducted from October 2015 to January 2022. Participants were followed up every 4 weeks for 24 weeks.

Fourteen sites in France and Monaco.

356 adult outpatients with alcohol use disorder were assessed for eligibility, and 337 were enrolled and randomly assigned (1:1) to receive active or sham stimulation. At baseline, the randomized participants were primarily male (60.5%) with an average age of 51.3 ± 11.3 years.

Two daily stimulation sessions (anode F4, cathode F3, 2 mA) delivered over five consecutive days vs. sham stimulation. Direct currents were applied via a pair of 0.9% NaCl-soaked surface sponge electrodes (25 cm²). In the sham stimulation group, the initial ramp-up time of 15 s (also up to 2 mA) was immediately followed by a ramp down phase of 30 seconds.

The co-primary outcomes were the change in the number of heavy drinking days (HDD) and total alcohol consumption (TAC) over the follow-up period. Exploratory secondary outcomes included alcohol craving, clinical and biological improvements, quality-of-life, mood, cognitive and safety assessments.

Over 24 weeks of follow-up, vs. sham, the active stimulation group reported statistically significant reductions in the number of HDD [-2.45 HDD/4 weeks, 97.5% confidence interval (CI) = -4.86 to -0.05, P = 0.022]. The reduction in TAC was not statistically significant (-5.96 g/day, 97.5% CI = -15.18 to 3.26, P = 0.147). The interpretation of these findings should take into account the proportion of missing data related to alcohol diary completeness and losses to follow-up. For secondary outcomes at 24 weeks, vs. sham, craving assessments were lower in the stimulation group (-0.36 95% CI = -0.65 to -0.07, P = 0.016), as were carbohydrate deficient transferrin levels (-0.33 95% CI = -0.65 to -0.01, P = 0.045). In the active vs. sham stimulation group, 69 (41.1%) and 62 participants (36.7%) experienced one or more adverse effects, resulting in 6 dropouts.

Among adult outpatients with alcohol use disorder, active transcranial direct current stimulation resulted in a modest but sustained reduction in heavy drinking days over 24 weeks, while no statistically significant effect was observed for total alcohol consumption. The intervention was well tolerated.