Recruiting

tDCS & Speech Therapy

Sponsor:

NYU Langone Health

Code:

NCT07222163

Conditions

Stuttering

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Interventions

Soterix Medical 1x1 tDCS system

Speech therapy sessions

Study Details

Brief summary:

The purpose of this study is to collect preliminary data on the efficacy of transcranial direct current stimulation (tDCS) combined with traditional behavioral techniques to reduce stuttering severity and negative impact in adults who stutter. The study also aims to explore neuroplastic changes (i.e., regional activation and functional connectivity) resulting from combined tDCS + speech therapy.

Conditions

Stuttering

Study ID

NCT07222163

Start date

Sep 4, 2025

Status verified date

Aug, 2026

Completion date

Dec 31, 2027

Anticipated

Primary completion date

Dec 31, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Adults aged 18 to 65 years.
2. Diagnosis of developmental stuttering, verified by a licensed speech-language pathologist.
3. Mild-to-moderate or greater stuttering severity, defined as a score of 20 or higher on the Stuttering Severity Instrument-Fourth Edition (SSI-4).
4. English as a primary language.
5. Right-handedness (to minimize variability in neural lateralization).
6. Willing and able to attend all study sessions and follow study procedures.

Exclusion Criteria:

1. Have a history of neurological, psychiatric, or medical conditions that are contraindicated for tDCS.
2. Are currently taking medications known to affect cortical excitability.
3. Have a history of seizures or epilepsy.
4. Are pregnant or planning to become pregnant during the study period.
5. Have metal implants in the head (excluding dental work) or other contraindications to electrical brain stimulation.
6. Any skin disorder or skin sensitive area near stimulation locations.

Study Design

Enrollment

16 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Behavioral speech therapy combined with active tDCS

Each participant will complete ten treatment sessions over approximately ten weeks. In each session, participants will receive active tDCS for 30 minutes while concurrently engaging in behavioral speech therapy. Active stimulation will include a 30-second ramp-up to 2.0 mA, 30 minutes of continuous stimulation, and a 30-second ramp-down.

sham comparator: Behavioral speech therapy combined with sham tDCS

Each participant will complete ten treatment sessions over approximately ten weeks. In each session, participants will receive sham tDCS for 30 minutes while concurrently engaging in behavioral speech therapy. Sham stimulation will involve the same ramp-up and ramp-down but with no current delivered during the 30-minute period to maintain blinding.

Interventions

Soterix Medical 1x1 tDCS system

Stimulation (2.0 mA for 30 minutes) will occur during speech therapy sessions focused on practicing speech techniques. Sham stimulation will mimic the physical sensation without active current.

Speech therapy sessions

Each of the ten weekly sessions will begin with 15 minutes of strategy practice, providing participants with the opportunity to rehearse light contact and easy onset techniques prior to the tDCS-enhanced speaking task.

Primary outcome measure

  • Change in Stuttering Severity Instrument - 4th Edition (SSI-4) total score [ Time Frame: Baseline, Visit 15 (~1-2 weeks post-intervention) ]
  • Change in the Wright and Ayre Stuttering Self-Rating Profile (WASSP) score [ Time Frame: Baseline, Visit 15 (~1-2 weeks post-intervention) ]
  • Stuttering impact as assessed by the Overall Assessment of the Speaker's Experience of Stuttering - Adults (OASES-A) [ Time Frame: Baseline, Visit 15 (~1-2 weeks post-intervention) ]
  • Change in the Brief Version of the Unhelpful Thoughts and Beliefs About Stuttering Scales (UTBAS-6) total score [ Time Frame: Baseline, Visit 15 (~1-2 weeks post-intervention) ]
  • Change in Brief Fear of Negative Evaluation (BFNE-S) Scale total score [ Time Frame: Baseline, Visit 15 (~1-2 weeks post-intervention) ]
  • Social Interaction Anxiety Scale (SIAS) [ Time Frame: Baseline, Visit 15 (~1-2 weeks post-intervention) ]

Central Contacts and Locations

Central contacts

Eric S. Jackson

212-992-9470Ej34@nyu.edu

Locations

NYU Langone Health

Recruiting

New York, New York, United States, 10016

More Information

Sponsor

NYU Langone Health

Last update posted

Sep 2, 2026

Last verified

Aug, 2026

Keywords

  • tDCS

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by NYU Langone Health on 2026-09-02.