StutteringNCT07222163
Stuttering and Neuromodulation
A study testing Soterix Medical 1x1 tDCS system and Speech therapy sessions in people with Stuttering, run by NYU Langone Health at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Stuttering
- What is being tested?
- Soterix Medical 1x1 tDCS system and Speech therapy sessions
- Type of treatment
- Medical device, Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 16 participants
- Where
- 1 siteUnited States
- Study dates
- 4 Sep 2025to 31 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18 to 65 years.
- Diagnosis of developmental stuttering, verified by a licensed speech-language pathologist.
- Mild-to-moderate or greater stuttering severity, defined as a score of 20 or higher on the Stuttering Severity Instrument-Fourth Edition (SSI-4).
- English as a primary language.
- Right-handedness (to minimize variability in neural lateralization).
- Willing and able to attend all study sessions and follow study procedures.
Who cannot join
- Have a history of neurological, psychiatric, or medical conditions that are contraindicated for tDCS.
- Are currently taking medications known to affect cortical excitability.
- Have a history of seizures or epilepsy.
- Are pregnant or planning to become pregnant during the study period.
- Have metal implants in the head (excluding dental work) or other contraindications to electrical brain stimulation.
- Any skin disorder or skin sensitive area near stimulation locations.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
NYU Langone Health
New York, New York, 10016
About this study
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
- Being tested
- Soterix Medical 1x1 tDCS system, Speech therapy sessions
- Keywords
- tDCS
- Medical subject headings
- Stuttering
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Soterix Medical 1x1 tDCS systemDevice
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 sessionsBehavioural
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.
| Study group | Role | What they receive |
|---|---|---|
| Behavioral speech therapy combined with active tDCS | Experimental | 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. Receives: Device: Soterix Medical 1x1 tDCS system; Behavioral: Speech therapy sessions |
| Behavioral speech therapy combined with sham tDCS | Sham comparator | 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. Receives: Device: Soterix Medical 1x1 tDCS system; Behavioral: Speech therapy sessions |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Stuttering Severity Instrument - 4th Edition (SSI-4) total score
The Stuttering Severity Instrument-4th Edition (SSI-4) provides a total score that is compared to age-specific norms to determine severity, with ranges for "Very Mild" to "Very Severe". The SSI-4 calculates individual scores for frequency (2-18), duration (2-18), and physical concomitants (0-20). These individual scores are combined to create a total score, which is then ranked against norms to provide a verbal severity descriptor, such as mild, moderate, severe, or very severe.
Measured: Baseline, Visit 15 (~1-2 weeks post-intervention)
Change in the Wright and Ayre Stuttering Self-Rating Profile (WASSP) score
The WASSP produces a profile of scores across five subscales. There is a total of 26 items each scored on a seven-point Likert-type scale. A score of '1' represents the least severe/negative perception, while a '7' represents the most severe/negative perception on each scale. Total scores range from 26-182, with higher scores indicating a greater negative impact of stuttering on their life.
Measured: 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)
The OASES-A is a tool used by speech-language pathologists to measure the adverse impact of stuttering on an adult's life. It consists of 100 questions rated on a 5-point scale (1-5). The scores from individual questions are added together to create an overall score. The total score is then used to determine the "Impact Rating" on a scale from mild to severe. Higher scores indicate higher levels of negative impact.
Measured: 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
The UTBAS-6 is a six-item screening questionnaire for adults who stutter to measure unhelpful thoughts and beliefs associated with speech anxiety. The UTBAS-6 has a subscale score range of 6 to 30 and a total score range of 18 to 90. A higher score indicates more frequent unhelpful thoughts and greater anxiety related to stuttering.
Measured: Baseline, Visit 15 (~1-2 weeks post-intervention)
Change in Brief Fear of Negative Evaluation (BFNE-S) Scale total score
The BFNE-S consists of 8 items that are rated on a five-point likert scale from 1 (not at all characteristic) to 4 (extremely characteristic). Scores range from 0 to 32. A score of 25 or higher may indicate clinically significant social anxiety.
Measured: Baseline, Visit 15 (~1-2 weeks post-intervention)
Social Interaction Anxiety Scale (SIAS)
The SIAS is a 20-item self-report questionnaire that measures the severity of social anxiety. Each item is rated from 0 (not at all characteristic or true of me) to 4 (extremely characteristic or ture of me). Scores can range from 0 (no social anxiety) to 80 (maximum social anxiety). A score of 36 or higher is often considered clinically significant, suggesting the presence of social anxiety.
Measured: Baseline, Visit 15 (~1-2 weeks post-intervention)
Secondary outcomes (2)
Change in regional activation in/between cognitive control and speech motor areas during a delayed-naming task
Neuroplastic changes will be assessed using functional near-infrared spectroscopy (fNIRS) to measure cortical activation patterns (i.e., regional activation, functional connectivity) in/between cognitive control and speech motor areas during a delayed-naming task (pre- and post-intervention).
Measured: Baseline, Visit 15 (~1-2 weeks post-intervention)
Change in functional connectivity in/between cognitive control and speech motor areas during a delayed-naming task
Neuroplastic changes will be assessed using functional near-infrared spectroscopy (fNIRS) to measure cortical activation patterns (i.e., regional activation, functional connectivity) in/between cognitive control and speech motor areas during a delayed-naming task (pre- and post-intervention).
Measured: Baseline, Visit 15 (~1-2 weeks post-intervention)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Oct 2025
- Study start4 Sep 2025
- Primary completion31 Dec 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for StutteringStudies of the same condition, open and under way.
- More trials run by NYU Langone HealthThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 16 participants (estimated)
Sponsor and investigators
- Lead sponsor
- NYU Langone Health
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Eric S. Jackson, Principal investigator, NYU Langone Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07222163
- Sponsor's protocol ID
- 25-00866
- Status last verified
- Aug 2026
- First submitted
- 28 Oct 2025
- Last updated
- 2 Sep 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: The de-identified participant data from the final research dataset will be shared upon reasonable request beginning 9 to 36 months after publication or as required by a condition of awards or supporting agreements, provided the requesting researcher provide a methodologically sound proposal and executes a data use agreement with NYU Langone Health. This instance of data sharing will also require separate IRB review as well as review from NYU Langone's Data Sharing Strategy Board (DSSB). Requests should be directed to: Ej34@nyu.edu. The protocol and statistical analysis plan will be posted on Clinicaltrials.gov only as required by federal regulation or supporting awards and agreements.
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Stuttering and Neuromodulation
- ClinicalTrials.gov ID
- NCT07222163
- Acronym / sponsor ID
- 25-00866
- Conditions
- Stuttering
- Keywords
- tDCS
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 16 participants (estimated)
- Lead sponsor
- NYU Langone HealthUniversity, hospital or other
- Study start
- 4 Sep 2025 (actual)
- Primary completion
- 31 Dec 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 29 Oct 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Behavioral speech therapy combined with active tDCS | Experimental | Device: Soterix Medical 1x1 tDCS system, Behavioral: Speech therapy sessionsEach 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. |
| Behavioral speech therapy combined with sham tDCS | Sham comparator | Device: Soterix Medical 1x1 tDCS system, Behavioral: Speech therapy sessionsEach 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. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Adults aged 18 to 65 years.
- Diagnosis of developmental stuttering, verified by a licensed speech-language pathologist.
- Mild-to-moderate or greater stuttering severity, defined as a score of 20 or higher on the Stuttering Severity Instrument-Fourth Edition (SSI-4).
- English as a primary language.
- Right-handedness (to minimize variability in neural lateralization).
Key exclusion criteria (6 listed)
- Have a history of neurological, psychiatric, or medical conditions that are contraindicated for tDCS.
- Are currently taking medications known to affect cortical excitability.
- Have a history of seizures or epilepsy.
- Are pregnant or planning to become pregnant during the study period.
- Have metal implants in the head (excluding dental work) or other contraindications to electrical brain stimulation.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Soterix Medical 1x1 tDCS systemStimulation (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. | Device | Behavioral speech therapy combined with active tDCS, Behavioral speech therapy combined with sham tDCS |
| Speech therapy sessionsEach 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. | Behavioural | Behavioral speech therapy combined with active tDCS, Behavioral speech therapy combined with sham tDCS |
Primary outcome
Change in Stuttering Severity Instrument - 4th Edition (SSI-4) total score
Time frame: Baseline, Visit 15 (~1-2 weeks post-intervention)
The Stuttering Severity Instrument-4th Edition (SSI-4) provides a total score that is compared to age-specific norms to determine severity, with ranges for "Very Mild" to "Very Severe". The SSI-4 calculates individual scores for frequency (2-18), duration (2-18), and physical concomitants (0-20). These individual scores are combined to create a total score, which is then ranked against norms to provide a verbal severity descriptor, such as mild, moderate, severe, or very severe.
Change in the Wright and Ayre Stuttering Self-Rating Profile (WASSP) score
Time frame: Baseline, Visit 15 (~1-2 weeks post-intervention)
The WASSP produces a profile of scores across five subscales. There is a total of 26 items each scored on a seven-point Likert-type scale. A score of '1' represents the least severe/negative perception, while a '7' represents the most severe/negative perception on each scale. Total scores range from 26-182, with higher scores indicating a greater negative impact of stuttering on their life.
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)
The OASES-A is a tool used by speech-language pathologists to measure the adverse impact of stuttering on an adult's life. It consists of 100 questions rated on a 5-point scale (1-5). The scores from individual questions are added together to create an overall score. The total score is then used to determine the "Impact Rating" on a scale from mild to severe. Higher scores indicate higher levels of negative impact.
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)
The UTBAS-6 is a six-item screening questionnaire for adults who stutter to measure unhelpful thoughts and beliefs associated with speech anxiety. The UTBAS-6 has a subscale score range of 6 to 30 and a total score range of 18 to 90. A higher score indicates more frequent unhelpful thoughts and greater anxiety related to stuttering.
Change in Brief Fear of Negative Evaluation (BFNE-S) Scale total score
Time frame: Baseline, Visit 15 (~1-2 weeks post-intervention)
The BFNE-S consists of 8 items that are rated on a five-point likert scale from 1 (not at all characteristic) to 4 (extremely characteristic). Scores range from 0 to 32. A score of 25 or higher may indicate clinically significant social anxiety.
Social Interaction Anxiety Scale (SIAS)
Time frame: Baseline, Visit 15 (~1-2 weeks post-intervention)
The SIAS is a 20-item self-report questionnaire that measures the severity of social anxiety. Each item is rated from 0 (not at all characteristic or true of me) to 4 (extremely characteristic or ture of me). Scores can range from 0 (no social anxiety) to 80 (maximum social anxiety). A score of 36 or higher is often considered clinically significant, suggesting the presence of social anxiety.
2 secondary outcomes
Change in regional activation in/between cognitive control and speech motor areas during a delayed-naming task
Time frame: Baseline, Visit 15 (~1-2 weeks post-intervention)
Change in functional connectivity in/between cognitive control and speech motor areas during a delayed-naming task
Time frame: Baseline, Visit 15 (~1-2 weeks post-intervention)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2026.
- Individual participant dataSharing planned: Yes. The de-identified participant data from the final research dataset will be shared upon reasonable request beginning 9 to 36 months after publication or as required by a condition of awards or supporting agreements, provided the requesting researcher provide a methodologically sound proposal and executes a data use agreement with NYU Langone Health. This instance of data sharing will also require separate IRB review as well as review from NYU Langone's Data Sharing Strategy Board (DSSB). Requests should be directed to: Ej34@nyu.edu. The protocol and statistical analysis plan will be posted on Clinicaltrials.gov only as required by federal regulation or supporting awards and agreements.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Eric S. Jackson principal investigator
NYU Langone Health
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Soterix Medical 1x1 tDCS system and Speech therapy sessions in people with Stuttering, run by NYU Langone Health at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Eric S. Jackson (212-992-9470, Ej34@nyu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Stuttering Severity Instrument - 4th Edition (SSI-4) total score (time frame: Baseline, Visit 15 (~1-2 weeks post-intervention)). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Sep 2026.