Page 74 - JCBP-2-3

Journal of Clinical and

Basic Psychosomatics

ORIGINAL RESEARCH ARTICLE
The effect of high-definition transcranial direct

current stimulation on pain in somatic symptom
disorder with predominant pain: A randomized

single-blind sham-controlled crossover study

Sanjana Kathiravan , Abhishek Ghosh , and Shubh Mohan Singh*
Department of Psychiatry, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Abstract
Somatic symptom disorder with predominant pain (SSD-P) is a commonly
encountered disorder, yet treatment options often yield unsatisfactory outcomes.
Transcranial direct current stimulation (tDCS) has proven useful in chronic pain
conditions and may hold potential for treating somatoform pain. High-definition tDCS
(HD-tDCS) offers more precise cortical stimulation than conventional tDCS. However,
this modality has not been extensively studied in SSD-P. Consequently, this study
aims to assess the effects of a novel HD-tDCS protocol on pain and other associated
variables in patients with SSD-P. The Institute Ethics Committee approved the study,
which was also registered in the Clinical Trials Registry of India. A single-blind, sham-
*Corresponding author: controlled, crossover study design was employed. Thirty right-handed patients with
Shubh Mohan Singh DSM-5 diagnosis of SSD-P, aged 18 – 60 years and receiving stable treatment, were
(singh.shubhmohan@pgimer.edu.in) enrolled through consecutive sampling. After simple randomization, two repeated,
Citation: Kathiravan S, Ghosh A, short-interval sessions (2 mA, 20 min each) of either active or sham HD-tDCS were
Singh SM. The effect of high- administered, followed by a washout period of 7 days and a subsequent crossover.
definition transcranial direct current Assessments were conducted at baseline, week 1, and week 2. Participants in active
stimulation on pain in somatic
symptom disorder with predominant and sham arms were comparable on all baseline parameters. At the end of the
pain: A randomized single-blind 1 week, patients in the active group showed significant improvement in the study
st
sham-controlled crossover variables compared to the sham group. By week 2, all participants, irrespective of
study. J Clin Basic Psychosom.
2024;2(3):2002. being in the active or sham arm, demonstrated a statistically significant difference
doi: 10.36922/jcbp.2002 (Cohen’s d > 0.8) in pain and associated parameters such as depression, anxiety,
Received: October 10, 2023 pain-related interference, burden, and disability (P < 0.01). Transient mild local side
effects such as burning, pain, and itching were noted, with no cognitive side effects
Accepted: May 9, 2024
reported. In conclusion, this novel HD-tDCS protocol is effective in reducing pain in
Published Online: July 16, 2024 patients with SSD-P, with sustained effects up to 1 week.
Copyright: © 2024 Author(s).
This is an Open-Access article
distributed under the terms of the Keywords: High definition transcranial direct current stimulation; HD-tDCS; Chronic pain;
Creative Commons Attribution Somatic symptom disorder; Crossover study, Sham-controlled study
License, permitting distribution,
and reproduction in any medium,
provided the original work is
properly cited.
1. Introduction
Publisher’s Note: AccScience
Publishing remains neutral with Pain can be defined as an unpleasant sensory and emotional experience associated with,
regard to jurisdictional claims in 1
published maps and institutional or resembling that associated with, actual or potential tissue damage. Inadequately
affiliations. explained pain can be classified under the category of somatoform disorders. Somatic

Volume 2 Issue 3 (2024) 1 doi: 10.36922/jcbp.2002