Inhibitory Control Training Enhanced by Transcranial Direct Current Stimulation to Reduce Binge Eating Episodes: Findings from the Randomized Phase II ACCElect Trial

Abstract

Introduction: Binge eating disorder (BED) is characterized by recurrent binge eating (BE) episodes with loss of control. Inhibitory control impairments, including alterations in dorsolateral prefrontal cortex (dlPFC) functioning, have been described for BED. A targeted modulation of inhibitory control circuits by the combination of inhibitory control training and transcranial brain stimulation could be promising. Objective: The aim of the study was to demonstrate feasibility and clinical effects of a transcranial direct current stimulation (tDCS)-enhanced inhibitory control training to reduce BE episodes and to generate an empirical basis for a confirmatory trial. Methods: We performed a monocentric clinical phase II double-blind randomized trial with two parallel arms. Forty-one adult outpatients with full-syndrome BED according to DSM-5 received six sessions of food-related inhibitory control training, randomly combined with 2 mA verum or sham tDCS of the right dlPFC. The main outcome was BE frequency within a 4-week interval after treatment termination (T8; primary) and at 12-week follow-up (T9; secondary) as compared to baseline. Results: BE frequency was reduced in the sham group from 15.5 to 5.9 (T8) and to 6.8 (T9); in the verum group, the reduction was 18.6 to 4.4 (T8) resp. 3.8 (T9). Poisson regression with the study arm as the factor and baseline BE frequency as the covariate revealed a p value of 0.34 for T8 and 0.026 for T9. Sham and real tDCS differed at T9 in BE frequency. Conclusions: Inhibitory control training enhanced by tDCS is safe in patients with BED and results in a substantial and sustainable reduction in BE frequency which unfolds over several weeks post-treatment. These results constitute the empirical basis for a confirmatory trial.