Functional and Affective Effects of a Brief tDCS Intervention in Fibromyalgia and Chronic Fatigue Syndrome (FibFatDCS)

May 1, 2026 updated by: Oznur Buran Sevik, Hospital Donostia
Functional and Affective Effects of a brief tDCS Intervention in Fibromyalgia and Chronic Fatigue Syndrome Fibromyalgia (FM) and chronic fatigue syndrome (CFS) are characterized by persistent, multidimensional symptoms arising from complex brain-body interactions that impair functioning and quality of life. Noninvasive neuromodulation techniques such as transcranial direct current stimulation (tDCS) have been proposed as adjunctive approaches to support short-term functional changes within distributed neural systems, although evidence remains limited and heterogeneous. The objective is to examine immediate pre-post changes in multidimensional clinical outcomes following a standardized tDCS protocol in patients with FM and CFS, and to explore potential diagnosis-related response patterns.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Abstract Background: Fibromyalgia (FM) and chronic fatigue syndrome (CFS) are characterized by persistent, multidimensional symptoms arising from complex brain-body interactions that impair functioning and quality of life. Noninvasive neuromodulation techniques such as transcranial direct current stimulation (tDCS) have been proposed as adjunctive approaches to support short-term functional changes within distributed neural systems, although evidence remains limited and heterogeneous. Objective: To examine immediate pre-post changes in multidimensional clinical outcomes following a standardized tDCS protocol in patients with FM and CFS, and to explore potential diagnosis-related response patterns. Methods: Fifteen patients (FM: n = 5; CFS: n = 10) received 10 sessions of tDCS (20 minutes per session) administered over two consecutive weeks (five sessions per week). Patient-reported outcomes were assessed at baseline and immediately after treatment completion. Measures included the Short Form-36 Health Survey (SF-36), Fibromyalgia Impact Questionnaire (FIQ), Hospital Anxiety and Depression Scale (HADS), Composite Autonomic Symptom Score (COMPASS), pain thermometer, Epworth Sleepiness Scale, Fatigue Severity Scale (FSS), and Fatigue Assessment Scale (FAS). Pre-post comparisons were conducted at the whole-sample level, followed by exploratory analyses stratified by diagnosis. Results: At baseline, patients with FM showed lower COMPASS, FSS, FAS, and HADS scores, and higher SF-36 scores, compared to patients with CFS, indicating a relatively less severe clinical profile. Across the sample, pre-post comparisons indicated improvements in FIQ and HADS scores. Exploratory group-specific analyses suggested that FM patients exhibited reductions in depressive symptoms, whereas CFS patients showed improvements in quality of life (SF-36) and functional impact (FIQ). No significant changes were observed in subjective pain intensity or fatigue severity (FSS). Conclusions: These findings suggest partially distinct clinical profiles and differential responsiveness to tDCS across FM and CFS, within the context of baseline differences between groups. Improvements appeared domain-specific, with affective symptoms responding in FM and functional outcomes in CFS, while core symptoms such as pain and fatigue remained unchanged over the intervention period. This pattern provides preliminary support for the idea that short-term neuromodulation may preferentially influence higher-order regulatory processes rather than core symptom generators, underscoring the need for tailored, multidimensional treatment approaches. Nevertheless, given the small sample size, absence of a control condition, and exploratory nature of subgroup analyses, these results should be interpreted with caution. Further controlled

studies are needed to clarify the reliability, specificity, and clinical relevance of these effects.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Spain
    • Gipuzkoa
      • San Sebastián, Gipuzkoa, Spain, 20250
        • Hospital Universitario DE Donostia

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Diagnosis of Fibromyalgia
  • Diagnosis of chronic fatigue syndrome

Exclusion Criteria:

  • Having both conditions at the same time

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: The patients with Fibromyalgia
The same treatment is applied (tDCS)
Device: Transcraneal Direct Current Electric Stimulation (tDCS)
It is an neuromodulation technic
Active Comparator: The patients with chronic fatigue syndrome
The same treatment is applied ( tDCS)
Device: Transcranial Direct Current Electric Stimulation (tDCS)
It is a neuromodulation technic

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Visual Pain Scores (VAS)
Time Frame: From enrollment to the end of treatment at 2 weeks
It is measured before and inmediately after the treatment ( tDCS) is applied. (0-10) Higher scores mean more pain.
From enrollment to the end of treatment at 2 weeks
Fibromyalgia Impact Questionnaire (FIQ)
Time Frame: From enrollment to the end of treatment at 2 weeks
It measures the impact of fibromyalgia (Scores: 0-100) The FIQ is scored in such a way that a higher score indicates a greater impact of the syndrome on the person.
From enrollment to the end of treatment at 2 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hospital Donostia

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Adolfo Lopez de Munain, Doctor, University Hospital of Donostia
  • Study Director: PEDRO MONTOYA, UNIVERSITY OF BALEARIC ISLANDS, MALLORCA

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

  • Moldofsky H. Fibromyalgia, sleep disorder and chronic fatigue syndrome. Ciba Found Symp. 1993;173:262-71; discussion 272-9. doi: 10.1002/9780470514382.ch15. PMID: 8491102.
  • McHorney CA, Ware JE Jr, Lu JF, Sherbourne CD. The MOS 36-item Short-Form Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups. Med Care. 1994 Jan;32(1):40-66. doi: 10.1097/00005650-199401000-00004. PMID: 8277801.
  • Lloyd, D. M., Wittkopf, P. G., Arendsen, L. J., & Jones, A. K. P. (2020). Is transcranial direct current stimulation (tDCS) effective for the treatment of pain in fibromyalgia? A systematic review and meta-analysis. The Journal of Pain, 21(11-12), 1085-1100. https://doi.org/10.1016/j.jpain.2020.01.003
  • Lerdal A, Kottorp A. Psychometric properties of the Fatigue Severity Scale-Rasch analyses of individual responses in a Norwegian stroke cohort. Int J Nurs Stud. 2011 Oct;48(10):1258-65. doi: 10.1016/j.ijnurstu.2011.02.019. Epub 2011 Mar 16. PMID: 21414620.
  • Hendriks C, Drent M, Elfferich M, De Vries J. The Fatigue Assessment Scale: quality and availability in sarcoidosis and other diseases. Curr Opin Pulm Med. 2018 Sep;24(5):495-503. doi: 10.1097/MCP.0000000000000496. PMID: 29889115
  • Hawker, G. A., et al. (2011).Measures of adult pain: Visual Analog Scale for Pain (VAS Pain). Arthritis Care & Research, 63(S11), S240-S252. https://doi.org/10.1002/acr.20543
  • Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome; Board on the Health of Select Populations; Institute of Medicine. Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness. Washington (DC): National Academies Press (US); 2015 Feb 10. 7, Recommendations. Available from: https://www.ncbi.nlm.nih.gov/books/NBK284910/
  • Burckhardt CS1, Clark SR, Bennett RM. The fibromyalgia impact questionnaire: development and validation.J Rheumatol. 1991 May;18(5):728-33.
  • Bartholomew EJ, Medvedev ON, Petrie KJ, Chalder T. Rasch analysis of the hospital anxiety and depression scale in patients with chronic fatigue syndrome. J Psychosom Res. 2025 Oct;197:112370. doi: 10.1016/j.jpsychores.2025.112370. Epub 2025 Sep 3. PMID: 40939313.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 30, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 21, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 1, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 7, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 7, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 1, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • #061CER24
  • European Regional Development (Other Identifier: grant #PID2022-140561NB-I00.)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

IPD may be shared upon reasonable request, subject to ethical approval and data use agreements.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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