MRI-tDCS Stress and Future Thinking Study

Modulation of the Stressed Brain: Effects of Transcranial Direct Current Stimulation on Stress Regulation and Episodic Future Thinking - an MRI Study in Healthy Volunteers

This academic study investigates how MRI-compatible transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) influences stress regulation and episodic future thinking in healthy volunteers. Participants undergo one MRI session: combining stress induction, tDCS (real or sham), and functional and metabolic MRI measurements. The study aims to better understand how non-invasive brain stimulation affects the neurophysiological and psychological mechanisms involved in stress processing and future-oriented thinking.

Study Overview

• Status: Completed
• Conditions: Healthy Participants
• Intervention / Treatment: Device: tDCS - Active non-invasive brain stimulation; Device: tDCS - Sham non-invasive brain stimulation

Detailed Description

The purpose of this study is to examine the modulatory effects of non-invasive brain stimulation on cognitive and emotional processes related to stress regulation and episodic future thinking (EFT).

Healthy adult volunteers complete one MRI session. Participants were randomly assigned to active or sham stimulation. First, participants performed an fMRI-based baseline measurement of the EFT task. This task involves imagining specific future personal events in response to cue words presented on a screen and later verbally describing these imagined events outside the scanner.

During the second part, participants complete the Montreal Imaging Stress Task (MIST) - a mental arithmetic paradigm with time pressure and negative feedback to induce acute stress. Immediately afterward, they receive MRI-compatible tDCS (active or sham) for 20 minutes while at rest. The active tDCS delivers 2 mA current through a 4×4 cm anode placed over the left DLPFC and a cathode over the contralateral orbitofrontal region. Sham stimulation follows the same setup with current ramping only at the onset and offset.

Following stimulation, an ASL perfusion scan, MRS spectroscopy targeting the hippocampus, and a post-stimulation EFT fMRI task were conducted. Throughout the MRI scan, behavioral and psychometric data were collected, including questionnaires on rumination, personality, and mood, as well as physiological and biochemical measures such as salivary cortisol and heart rate variability (HRV).

The primary goal is to assess whether active tDCS modulates the neural, endocrine, and behavioral correlates of stress and future-oriented cognition compared to sham stimulation.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Brussels Capital
    • Brussels, Brussels Capital, Belgium, 1090
      • UZ Brussel

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Men and women aged 18-30 years.
• Right-handed, healthy volunteers.
• Native Dutch speakers with normal or corrected vision.
• No current or past psychiatric or neurological disorder.
• MRI-compatible (no metal implants, pacemaker, etc.).
• Not taking psychotropic medication.
• Provided written informed consent.

Exclusion Criteria:

• Pregnancy.
• History of epilepsy or neurosurgery.
• Cardiovascular, neurological, or severe medical illness.
• Claustrophobia or intolerance to MRI environment.
• Tattoos or piercings that cannot be removed.
• Alcohol or caffeine consumption within the restricted window before scanning.
• Current use of psychoactive substances or psychotropic drugs.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Active Transcranial direct current stimulation; Participants receive MRI-compatible transcranial direct current stimulation (tDCS) using a constant current of 2 mA applied for 20 minutes. The anodal electrode (4 × 4 cm) is positioned over the left dorsolateral prefrontal cortex (F3 position, neuronavigated) and the cathodal electrode over the contralateral orbitofrontal region. Stimulation is delivered while participants are in the MRI scanner.	Device: tDCS - Active non-invasive brain stimulation; active non-invasive brain stimulation
Placebo Comparator: Sham Transcranial direct current stimulation; Participants receive sham MRI-compatible transcranial direct current stimulation using the same electrode placement and setup as the active condition. The current is ramped up and down for approximately 30 seconds at the beginning of the session to mimic the initial sensation of stimulation, after which no current is delivered for the remainder of the 20-minute session. Stimulation is administered while participants are in the MRI scanner.	Device: tDCS - Sham non-invasive brain stimulation; Sham non-invasive brain stimulation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Specificity score of episodic future thinking	Specificity of episodic future thinking responses assessed using a standardized scoring procedure applied to imagined future events. Unit of Measure: EFT specificity score (units on a standardized scale)	Baseline and immediately post-tDCS (single study visit)
Momentary mood ratings - fatigue	Self-reported tension measured using a visual analogue scale (VAS) Unit of Measure:Score on a 0-10 scale. A higher score means more fatigued.	Baseline; immediately post-tDCS; and immediately post-EFT paradigm (single study visit)
Mean BOLD signal change during episodic future thinking	Mean blood-oxygen-level-dependent (BOLD) signal change during the episodic future thinking task, averaged across predefined prefrontal-limbic regions of interest. Unit of Measure: Percent signal change (or beta coefficients from the general linear model)	Baseline and immediately post-tDCS (single study visit)
Momentary mood ratings -tension	Self-reported tension measured using a visual analogue scale (VAS) Unit of Measure: Score on a 0-10 scale. A higher score means more tensed.	Baseline; immediately post-tDCS; and immediately post-EFT paradigm (single study visit)
Momentary mood ratings - vigor	Self-reported vigor measured using a visual analogue scale (VAS). Unit of Measure: Score on a 0-10 scale. A higher score means more vigor.	Baseline; immediately post-tDCS; and immediately post-EFT paradigm (single study visit)
Momentary mood ratings - anger	Self-reported anger measured using a visual analogue scale (VAS). Unit of Measure: Score on a 0-10 scale. A higher score means more anger.	Baseline; immediately post-tDCS; and immediately post-EFT paradigm (single study visit)
Momentary mood ratings - depressed mood	Self-reported depressed mood measured using a visual analogue scale (VAS). Unit of Measure: Score on a 0-10 scale. A higher score means more depressed mood.	Baseline; immediately post-tDCS; and immediately post-EFT paradigm (single study visit)
Momentary mood ratings - cheerfulness	Self-reported cheerfulness measured using a visual analogue scale (VAS). Unit of Measure: Score on a 0-10 scale. A higher score means more cheerfulness.	Baseline; immediately post-tDCS; and immediately post-EFT paradigm (single study visit)
Momentary mood ratings - stress	Self-reported stress measured using a visual analogue scale (VAS). Unit of Measure: Score on a 0-10 scale. A higher score means more stress.	Baseline; immediately post-tDCS; and immediately post-EFT paradigm (single study visit)
Hippocampal glutamate concentration	Hippocampal glutamate concentration measured using proton magnetic resonance spectroscopy (¹H-MRS). Unit of Measure: Institutional units	Baseline and immediately post-tDCS (single study visit)
Hippocampal GABA concentration	Hippocampal gamma-aminobutyric acid (GABA) concentration measured using proton magnetic resonance spectroscopy (¹H-MRS). Unit of Measure: Institutional units	Baseline and immediately post-tDCS (single study visit)
Hippocampal glutamine concentration	Hippocampal glutamine concentration measured using proton magnetic resonance spectroscopy (¹H-MRS).	Baseline and immediately post-tDCS (single study visit)
Hippocampal N-acetylaspartate (NAA) concentration	Hippocampal N-acetylaspartate (NAA) concentration measured using proton magnetic resonance spectroscopy (¹H-MRS). Unit of Measure: Institutional units	Baseline and immediately post-tDCS (single study visit)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Salivary cortisol concentration	Salivary cortisol concentration measured using biochemical assay from saliva samples. Unit of Measure: nmol/L (or µg/dL)	Baseline, immediately post-tDCS, and immediately post-EFT task (single study visit)
Cerebral blood flow	Cerebral blood flow measured using arterial spin labeling (ASL) MRI. Unit of Measure: mL/100 g/min	Baseline and Periprocedural (during tDCS)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Depressive symptom severity	Beck Depression Inventory (BDI-II) The BDI-II consists of 21 items, each scored 0-3. Unit of Measure: BDI-II total score ranging from 0 to 63. Higher scores indicate more depressive symptoms.	Baseline (prior to any intervention)
Body mass index	Body mass index calculated from measured body weight and height.	Baseline (prior to any intervention)
Trait rumination	Trait rumination assessed using the Ruminative Responses Scale (RRS). Unit of Measure: RRS total score (range 22-88; higher scores indicate greater trait rumination).	Baseline (prior to any intervention)
Brooding rumination	Brooding rumination assessed using the Brooding subscale of the Ruminative Responses Scale (BSRI). Unit of Measure: BSRI (Brooding) subscale score, range 5-20; higher scores indicate greater brooding rumination.	Baseline (single study visit)
Trait anxiety	Trait anxiety assessed using the State-Trait Anxiety Inventory, Trait version (STAI-T). Unit of Measure: STAI-T total score (range 20-80; higher scores indicate greater trait anxiety).	Baseline (single study visit)

Collaborators and Investigators

• Sponsor: Universitair Ziekenhuis Brussel

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2018
• Primary Completion (Actual): September 1, 2018
• Study Completion (Actual): October 1, 2021

Study Registration Dates

• First Submitted: November 26, 2025
• First Submitted That Met QC Criteria: February 5, 2026
• First Posted (Actual): February 12, 2026

Study Record Updates

• Last Update Posted (Actual): February 12, 2026
• Last Update Submitted That Met QC Criteria: February 5, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: MRI; tDCS; fMRI; Cortisol; Mood; Spectroscopy; ASL; Episodic Future Thinking; Stress Regulation
• Other Study ID Numbers: tDCS FTS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No