Transcranial Direct Current Stimulation as Treatment for Major Depression in a Home Treatment Setting (HomeDC Trial): Study Design and Methodology of a Double-blind, Placebo-controlled Pilotstudy

Abstract

Introduction Transcranial direct current stimulation (tDCS) of prefrontal cortex regions has been reported to exert therapeutic effects in major depressive disorder (MDD). Due to its beneficial safety profile, its easy mode of application and its cost-effectiveness, tDCS has recently been proposed for treatment at home, which would offer new chances for regionally wide spread and long-term application. However, tDCS at home has to meet new methodological challenges of handling and adherence, and data from randomized controlled trials (RCT) investigating this mode of application are still lacking. In this pilot RCT, we therefore investigate feasibility, safety and effectiveness of a new tDCS application set-up in MDD. Methods and analysis The HomeDC trial will be conducted as a double-blind, placebo-controlled, parallel-group design trial. Thirty-two patients with MDD will be randomized to active or sham tDCS. Patients will self-administer prefrontal tDCS for 6 weeks. Active tDCS will be conducted with anode over F3, cathode over F4, for 5 sessions/week, with a duration of 30min/day and 2mA stimulation intensity, whereas sham tDCS follows the identical protocol in electrode montage and timing but with ramp-in and ramp-out periods only without intermittent stimulation. Both conditions will be administered as monotherapy or adjunctive treatment to a stable dose of antidepressant medication. Feasibility, effectiveness and safety will be assessed, and adjunctive fMRI and e-field modelling will be conducted at baseline. Discussion For the HomeDC trial, technical requirements of a placebo-controlled trial in a home-based treatment setting with tDCS have been established. It addresses the crucial points of a home-based treatment approach with tDCS: uniform electrode positioning and frequent monitoring of stimulation parameters and adherence, ensuring an appropriate home treatment environment. This study will allow identifying constraints and further critical topics of this novel mode of application. Trial Registration www.clinicaltrials.gov. Trial registration number: NCT05172505. Registration date: 12/13/2021, https://clinicaltrials.gov/ct2/show/NCT05172505