Assessing the effectiveness of high-definition transcranial direct current stimulation for treating obsessive-compulsive disorder: Results from a randomized, double-blind, controlled trial

Characterized by its disabling nature, obsessive compulsive disorder (OCD) affects individuals profoundly, with nearly 40% of patients showing resistance to initial treatment methods. Despite being safe and easily accessible, transcranial direct current stimulation (tDCS) lacks extensive substantiation supporting its efficacy in treating OCD. The objective of this study was to evaluate how cathodal high-definition transcranial direct current stimulation (HD-tDCS) applied to the right orbitofrontal cortex affected patients with OCD in terms of efficacy. 47 patients with OCD were enrolled. They were randomly allocated to active or sham stimulation groups, and underwent HD-tDCS stimulation treatment for 2 weeks. The central electrode located in the right orbitofrontal cortex region was cathodic. The severity of the patients' obsessive-compulsive symptoms, depression and anxiety were assessed before and after treatment. Out of the total, 44 patients concluded the treatment, comprising 23 participants from the active stimulation group and 21 from the sham stimulation group. Notably, substantial reductions in symptoms related to OCD, depression, and anxiety were exhibited in both groups. With a response rate of 26.1% in the active stimulation group and 23.8% in the sham stimulation group, there was no significant difference in efficacy observed. Furthermore, the reduction in depression and anxiety symptoms at the conclusion of the treatment was not notably superior in the active stimulation group. This study provided evidence for the acceptability and safety of HD-tDCS. Nevertheless, the study did not reveal notable clinical effectiveness of tDCS in addressing moderate to severe OCD in comparison to the sham stimulation group.