Transcranial Direct Current Stimulation Potentiation of Fear Extinction in OCD

August 15, 2026 updated by: Joan A Camprodon, MD MPH PhD, Massachusetts General Hospital

Transcranial Direct Current Stimulation Potentiation of Fear Extinction in OCD: Towards Rational Design of Combination Therapies

The investigators want to learn more about how human beings learn not to fear and the impact of changing the fear network in the brain using transcranial Direct Current Stimulation (tDCS) in individuals with obsessive compulsive disorder (OCD). The investigators hope this study will help us understand how future treatments can help patients with OCD better control unwanted fear.

Study Overview

Status

Status

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

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

To address this question behaviorally and biologically, the investigators will use a, 2-day fear extinction paradigm while measuring behavioral psychophysiology (skin conductance response [SCR]) and neurophysiology (electroencephalography [EEG]). On Day 1 participants will undergo 1) habituation, 2) fear conditioning, and 3) extinction learning. On Day 2 they will undergo 4) extinction recall, and 5) reinstatement. SCR and EEG will be measured in both sessions. The investigators propose to investigate whether inhibitory tDCS to the pre-SMA before, during, or after fear extinction significantly 1) enhances the recall of extinction learning and 2) reduces fronto-medial theta power during extinction recall. Participants will be randomized to one of the following four conditions: active tDCS before, during, or after extinction learning, or sham tDCS. The fear extinction paradigm serves as a proxy of exposure-based CBT for OCD. Defining the combination protocol that optimally and significantly increases extinction recall behaviorally (psychophysiology) in OCD, will have critical implications for the mechanistically informed development of tDCS-augmented CBT for OCD. EEG measures will provide a response biomarker to characterize target engagement neurophysiologically. This is particularly relevant given EEG's ease of use, relatively low cost, and potential for greater translation to the clinic. Also, the higher signal-to-noise ratio (SNR) of EEG compared to SCR is a strength. Taken together, these data should reveal treatment targets, define optimal therapeutic protocols, and provide the foundation for a future clinical trial to test the synergistic efficacy of combined tDCS-CBT for OCD.

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.
86

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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital

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

18 years to 60 years (Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Fluent in English, willing to provide informed consent, and willing to comply with the study protocol
  • Primary OCD that causes at least moderate distress and/or impairment (Y-BOCS total score ≥ 16)
  • Comfortable and capable of using a computer and completing computerized tasks

Exclusion Criteria:

  • History of head injury resulting in prolonged (i.e., >1h) loss of consciousness and/or neurological sequelae; history of stroke; signs of increased intracranial pressure; prior neurosurgical procedure (e.g., DBS, aneurysm clips)
  • Contraindications to participate in tDCS including: metallic implants in head or neck; ventriculoperitoneal (VP) shunts; pacemakers; pregnancy; epilepsy.
  • Current or history of neurologic or psychiatric disease (e.g., mental retardation, dementia, brain damage, or other cognitive impairment) that would interfere with ability to participate in the study
  • Impaired (or uncorrected) vision that would interfere with participation.
  • Current clinically significant suicidality that requires psychiatric hospitalization, as indicated by clinical judgment.
  • Current substance use disorder (within the past 12 months)
  • Lifetime manic episode or psychosis
  • Documented resistance to 4 or more valid pharmacological trials and previous treatment with ≥12 sessions of cognitive behavioral therapy for OCD with no response (or worsening symptoms)
  • Use of most psychotropic medications (e.g., SSRIs and atypical antipsychotics) will be allowed. However, use of benzodiazepines within 2 weeks prior to the study is exclusionary (and participants will be asked to refrain from use of such medications during the study as they may interfere with the fear extinction paradigm).
  • Unable to obtain low enough impedance values to ensure safe and effective application of tDCS/EEG.

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: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

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.
Experimental: Active tDCS administered before extinction phase
The investigators will stimulate using 2mA of direct current during 20 min before the extinction phase of the fear conditioning and extinction paradigm.
Device: Active tDCS
The investigators will use commercially available tDCS equipment (Neuroelectrics©, Barcelona, Spain). The cathode will be placed over the pre-SMA using the 10-20 EEG system and the anode will be on the right deltoid.
Experimental: Active tDCS administered during extinction phase
The investigators will stimulate using 2mA of direct current during 20 min during the extinction phase of the fear conditioning and extinction paradigm.
Device: Active tDCS
The investigators will use commercially available tDCS equipment (Neuroelectrics©, Barcelona, Spain). The cathode will be placed over the pre-SMA using the 10-20 EEG system and the anode will be on the right deltoid.
Experimental: Active tDCS administered after extinction phase
The investigators will stimulate using 2mA of direct current during 20 min after the extinction phase of the fear conditioning and extinction paradigm.
Device: Active tDCS
The investigators will use commercially available tDCS equipment (Neuroelectrics©, Barcelona, Spain). The cathode will be placed over the pre-SMA using the 10-20 EEG system and the anode will be on the right deltoid.
Sham Comparator: Sham tDCS
Sham will consist of a ramp up and down of activity (from 0 to 2mA and back to 0mA) in the first 30sec and again in the last 30 sec of the 20min stimulation period (which will occur before/during/after the extinction phase). No active tDCS will occur.
Device: Sham tDCS
The investigators will use commercially available tDCS equipment (Neuroelectrics©, Barcelona, Spain). The cathode will be placed over the pre-SMA using the 10-20 EEG system and the anode will be on the right deltoid. tDCS will not be active in this condition.

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
Difference in Frontomedial Theta Power (EEG) to the Conditioned Stimulus (CS+) Versus the Unconditioned Stimulus (CS-) Between tDCS Conditions During Extinction Recall
Time Frame: Extinction Recall Phase (Day 2)
Greater reduction in the difference in frontomedial theta event-related spectral perturbation (ERSP) between CS+ vs CS- indicates more complete neural extinction of the conditioned fear response, reflecting diminished differential threat processing such that the previously conditioned stimulus is being processed more similarly to the safe stimulus.
Extinction Recall Phase (Day 2)
Difference in the Square Root Skin Conductance Response (SCR) to the Conditioned Stimulus (CS+) Versus the Unconditioned Stimulus (CS-) Between tDCS Conditions During the First 12 Trials of Extinction Recall
Time Frame: Extinction Recall Phase (Day 2)
Higher skin conductance (microSiemens) indicates greater fear intensity.
Extinction Recall Phase (Day 2)

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.
Massachusetts General Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Foundation for OCD Research

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.
  • Principal Investigator: Joan Camprodon, MD, MPH, PhD, Massachusetts General Hospital

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.

Helpful Links

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.
September 15, 2022

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.
July 31, 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.
July 31, 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).
August 26, 2022

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.
August 26, 2022

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.
August 30, 2022

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.
September 4, 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.
August 15, 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.
July 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.
  • 2022P001065

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The investigators do not have specific plans to share individual participant data in order to preserve the confidentiality of our participants. Any data that is shared would only be done so after executing a formal Data Use Agreement from Massachusetts General Hospital.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

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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