Adjunctive duration-doubled transcranial direct current stimulation for the treatment of depressive patients with suicidal ideation: study protocol for a double-blind, randomized, sham-controlled trial

Abstract

Background: The problem of suicide has become increasingly common in individuals with major depressive disorder (MDD). Transcranial direct current stimulation (tDCS) is an effective treatment for MDD with 2 milliamperes (mA) for at least 30 min per day for 2 weeks. This study aims to investigate the efficacy of daily duration-doubled tDCS as an adjunctive intervention for rapidly reducing suicidal ideation and improving depression in MDD patients.

Methods: In this double-blind, randomized, sham-controlled study, 76 MDD patients with suicidal ideation are randomly assigned to either active (n=38) or sham (n=38) tDCS group. The anode and cathode are placed over the scalp areas corresponding to left and right dorsolateral prefrontal cortex (DLPFC), respectively, and each stimulation lasts for 60 min. The primary outcome is defined as change of Beck Scale for Suicide Ideation (BSI) after 5 and 10 sessions. The change of other clinical assessments, blood biomarkers related to suicidal ideation and depressive sumptoms are defined as secondary outcomes. Blood biomarkers related to suicidal ideation are collected at baseline and after 10 sessions.

Discussion: This study suggests the adjunctive duration-doubled tDCS might be a novel method to rapidly reduce suicidal ideation and improve depressive symptom. The variation of biomarkers could be potential predictive models of suicide risk.

Trial registration: The trial protocol is registered with ClinicalTrials.gov under protocol registration number NCT05555927. Registered on September 25, 2022.

Keywords: Major depressive disorder (MDD); Randomized controlled trial (RCT); Suicidal ideation; Transcranial direct current stimulation (tDCS).

Fig. 1

Trial flowchart. We plan to recruit 76 patients with MDD. For the patients who take no psychotropic drug at baseline or maintain actual pharmacotherapy for at least 2 weeks before the stimulation initiation and during the whole stimulation period. The patients will be randomized (1:1) into one of the following two groups: tDCS group or sham group. Primary and secondary study parameters will be accessed at baseline (week 0), the 1st week (after 5 sessions), 2nd week (after 10 sessions), 4th week (2 weeks after intervention), 6th week (4 weeks after intervention), and 8th week (6 weeks after intervention)