JMIR Publications

ABSTRACT

Background:

Major depressive disorder (MDD) is a severe illness that is the second-highest worldwide cause of disability. Standard treatments for MDD include medicine and talk therapy, but approximately 1 in 5 Canadians fail to respond to these approaches and must consider alternatives. Transcranial direct current stimulation (tDCS) is a safe, non-invasive method of using electrical stimulation to change the activation pattern of different brain regions. By targeting those regions known to be affected in MDD, tDCS may be useful in ameliorating treatment-resistant depression.

Objective:

The objective of the NESBID trial is to compare the effectiveness of active versus sham tDCS in treating patients with ultra-resistant MDD. The primary outcome will be the change on the Mongtomery-Asberg Depression Rating Scale (MADRS), which is an objective measure of depression severity. Secondary outcomes will include the change on the Quick Inventory of Depressive Symptomatology Scale (subjective assessment), and on the WHO Disability Assessment Schedule 2.0 (functional assessment). Adverse events will be captured using the Young Mania Rating Scale, tDCS Adverse Events Questionnaire, Frequency, Intensity and Burden of Side Effects Rating Scale (FIBSER), and Patient-Rated Inventory of Side Effects Scale (PRISE). A parallel component of the study will involve assaying for baseline language function, and the effect of treatment on language, using an exploratory acoustic and semantic corpus analysis on recorded entrance and exit interviews. Participant accuracy and response latency on an auditory lexical decision task will also be evaluated.

Methods:

We will recruit inpatients and outpatients in the city of Edmonton, Alberta, and will deliver the study interventions at the Grey Nuns and University of Alberta Hospitals. Written informed consent will be obtained from all participants prior to their enrolment. Eligible participants will be randomly assigned, in a double-blinded fashion, to receive either active or sham tDCS, and will continue receiving their usual pharmacotherapy and psychotherapy throughout the trial. In both groups participants will receive 30 weekday stimulation sessions, each session being 30 minutes in length, with the anode over the left dorsolateral prefrontal cortex and cathode over the right dorsolateral prefrontal cortex. Participants in the active group will be stimulated at 2 mA throughout, whereas the sham group will receive only a brief period of stimulation to mimic skin sensations felt in the active group. Measurements will be conducted at regular points throughout the trial, and thirty days after trial completion.

Results:

The trial has been approved by the University of Alberta Research Ethics Board and is scheduled to commence in September of 2020. The target sample size is 60 participants.

Conclusions:

This is a protocol for a multicenter, double-blinded, randomized controlled superiority trial comparing active versus sham tDCS in patients with treatment-resistant MDD. Clinical Trial: ClinicalTrials.gov (NCT04159012)