Reducing stuttering with mild brain stimulation plus speech therapy

Stuttering and Neuromodulation

Not applicable Interventional NYU Langone Health · NCT07222163

We will test whether mild electrical brain stimulation (tDCS) combined with speech therapy can reduce stuttering severity in adults who stutter.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment16 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorNYU Langone Health Academic / other
Locations1 site (New York, New York)
Trial IDNCT07222163 on ClinicalTrials.gov

What this trial studies

This interventional pilot collects preliminary data on combining transcranial direct current stimulation (tDCS) with standard speech therapy in adults with developmental stuttering. Participants who meet entry criteria will receive tDCS using a Soterix device alongside behavioral speech sessions while clinicians track stuttering severity and patient-reported impact. The study also measures neuroplastic changes, including regional brain activation and functional connectivity, to explore mechanisms of change. Enrollment is limited to right-handed, English-speaking adults aged 18–65 and is conducted at NYU Langone Health.

Who should consider this trial

Good fit: Ideal candidates are right-handed English-speaking adults aged 18–65 with developmental stuttering and an SSI-4 score of 20 or higher who can attend all onsite sessions at NYU Langone.

Not a fit: People with a history of seizures or epilepsy, certain medications affecting cortical excitability, pregnancy, metal head implants, or sensitive skin near stimulation sites are excluded and unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the combined approach could reduce stuttering severity and lessen the negative impact on everyday communication for adults who stutter.

How similar studies have performed: Small prior trials of tDCS combined with speech therapy have reported mixed but promising preliminary improvements in fluency, though larger confirmatory studies remain limited.

Eligibility criteria

Show full inclusion / exclusion criteria
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.

Where this trial is running

New York, New York

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions StutteringtDCS
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.