Autism Spectrum Disorder (ASD)NCT06878326
Resting-State Functional Connectivity as a Predictor of tDCS Effects in Adolescents With Autism Spectrum Disorder
A study testing tDCS in people with Autism Spectrum Disorder (ASD) and Transcranial Direct Current Stimulation (tDCS), run by The Hong Kong Polytechnic University at 1 site in Hong Kong.
Trial summary
Background: Transcranial Direct Current Stimulation (tDCS) is a form of non-invasive brain stimulation that has aroused increased interests in the past decade. Not only that it is transient with little side-effects, and can be well-tolerated by children, it is also affordable and readily accessible, making it an… Read more about this study
- Who is it for?
- Ages 12 to 22 years
- Conditions the study is for
- Autism Spectrum Disorder (ASD), Transcranial Direct Current Stimulation (tDCS), Electroencephalography
- What is being tested?
- tDCS
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 90 participants
- Where
- 1 siteHong Kong
- Study dates
- 1 Sep 2025to Apr 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 12 to 22 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- being 12-22 years old
- diagnosed with ASD given by registered psychiatrists or clinical psychologists according to the Diagnostic and Statistical Manual of Mental Disorders-5th Edition (DSM-5) criteria of ASD
- able to communicate in Chinese
Who cannot join
- without a confirmed diagnosis from the clinical psychologist
- history of other neurological and psychiatric disorders and head trauma
- on psychiatric medication
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Hong Kong1 site, 1 recruiting
- Recruiting
The Hong Kong Polytechnic University
Hung Hom, Kowloon
Yvonne Han, PhD, +852 2766 7578
About this study
Background: Transcranial Direct Current Stimulation (tDCS) is a form of non-invasive brain stimulation that has aroused increased interests in the past decade. Not only that it is transient with little side-effects, and can be well-tolerated by children, it is also affordable and readily accessible, making it an appealing treatment option for autism spectrum disorder (ASD).
Objective: (1) To evaluate the therapeutic effects of tDCS on improving cognitive function in patients with ASD, (2) to better understand the neural mechanisms underlying the neuromodulation effects of tDCS in patients with ASD, and (3) to determine whether resting-state functional connectivity measures can predict the therapeutic effects of active tDCS in individuals with ASD.
Read more
Methods: To assess the therapeutic effects and neural mechanisms of tDCS, 90 adolescents with ASD (age 12-22 years) will receive three stimulation conditions: cathodal tDCS of the left DLPFC, anodal tDCS of the left DLPFC and sham-tDCS with at least a week apart each time. During the active tDCS or sham-tDCS condition, the participants will be administered a computerized test battery (Cambridge Neuropsychological Test Automated Battery, CANTAB®) to evaluate their cognitive function. EEG before and after the tDCS to evaluate the tDCS-induced alteration in their neural activity and functional connectivity.
Hypothesis: Drawing together the different evidence linking ASD with cortical hyper-excitability and disordered neural connectivity, as reviewed previously, the investigators hypothesize that, relative to a sham-tDCS condition, active cathodal (inhibitory) and anodal (excitatory) tDCS over the left DLPRC will induce stimulation-linked facilitation of learning and resultant improvement of cognitive functioning in patients with ASD.
In addition to the therapeutic effects of tDCS, enhanced neural connectivity, as indexed by altered level EEG theta coherence in patients with ASD, will mediate the beneficial effects of tDCS, relative to sham tDCS, on improvements in cognitive function. Moreover, resting-state functional connectivity will moderate the beneficial effects of active tDCS on cognitive function, relative to sham tDCS, such that participants with greater pre-treatment resting state functional connectively will evidence greater/less response to tDCS, relative to participants receiving sham tDCS.
- Conditions
- Autism Spectrum Disorder (ASD), Transcranial Direct Current Stimulation (tDCS), Electroencephalography
- Being tested
- tDCS
- Medical subject headings
- Autism Spectrum Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
tDCSDevice
Participant will receive three stimulation conditions: cathodal tDCS of the left DLPFC, anodal tDCS of the left DLPFC and sham-tDCS. The order of the conditions will be randomized and counterbalanced across participants, and the three stimulation conditions will be administered at least a week apart to avoid carry-over effects. The tDCS session will last for 20 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Cathodal active tDCS | Experimental | For cathodal tDCS condition, participants will receive cathodal stimulation on the dorsolateral prefrontal cortex with ramp up and ramp down mode for 10 seconds, eliciting a tingling sensation on the scalp that fades over seconds. Following that, a twenty-minute executive functional task will be initiated five minutes subsequent to the stimulation mode, and the stimulation will be terminated when the task ends. Receives: Device: tDCS |
| Anodal active tDCS | Experimental | For anodal tDCS condition, participants will receive anodal stimulation on the dorsolateral prefrontal cortex with ramp up and ramp down mode for 10 seconds, eliciting a tingling sensation on the scalp that fades over seconds. Following that, a twenty-minute executive functional task will be initiated five minutes subsequent to the stimulation mode, and the stimulation will be terminated when the task ends. Receives: Device: tDCS |
| Sham tDCS | Sham comparator | For sham-tDCS condition, participants will receive initial stimulation with ramp up and ramp down mode for 30 seconds, eliciting a tingling sensation on the scalp then it will be discontinued. Participant will also receive the twenty-minute executive functional task five minutes subsequent to the stimulation mode. Receives: Device: tDCS |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in CANTAB® cognitive test - Reaction Time (RTI)
RTI assesses motor and mental response speeds, reaction time, response accuracy and impulsivity. It consists of 30 trials with five potential targets and requires participants to make flexible responses as fast as possible to the target stimulus (shown in yellow). Specifically, movement and reaction time will be measured, where shorter duration reflects faster processing speed.
Measured: During each stimulation session, last around 3mins
Change in CANTAB® cognitive test - Spatial Working Memory (SWM)
SWM assesses retention and manipulation of visuospatial information. The participant should find one yellow "token" in each of a number of boxes and use them to fill up an empty column on the right of the screen by selecting the boxes and using a process of elimination. Error selecting boxes that have already been found to be empty and revisiting boxes which have already been found to contain a token will be measured.
Measured: During each stimulation session, last around 6mins
Change in CANTAB® cognitive test - Multitasking Test (MTT): Response Latencies
MTT assesses the ability to resolve the interference of task-irrelevant information (stroop-like effect). The test displays an arrow which can appear on either the left or right side of the screen and can point to either the left or right side. In each trial, participants are presented with a cue that indicates which button to press according to two different rules. And the rules that participants have to follow may change from trial to trial in a randomized order. Participant's response latencies will be measured.
Measured: During each stimulation session, last around 8mins
Change in CANTAB® cognitive test - Multitasking Test (MTT): Error Scores
MTT assesses the ability to resolve the interference of task-irrelevant information (stroop-like effect). The test displays an arrow which can appear on either the left or right side of the screen and can point to either the left or right side. In each trial, participants are presented with a cue that indicates which button to press according to two different rules. And the rules that participants have to follow may change from trial to trial in a randomized order. Participant's error scores will be measured.
Measured: During each stimulation session, last around 8mins
Changes in EEG theta coherence
Each participant will be tested individually to collect EEG data. The participants' eyes-open resting condition will be assessed by EEG for 5 minutes, before and after the tDCS to evaluate the tDCS-induced alteration in their neural activity and functional connectivity. Raw data will be processed with the EEGLAB Toolbox using MATLAB® R2019a. Data from 19 electrodes will be used for analysis.
Measured: Before tDCS session, Right after tDCS session (2 timepoints, up to 20 minutes)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Mar 2025
- Study start1 Sep 2025
- Primary completionApr 2027 (estimated)
- Study completionApr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Autism Spectrum Disorder (ASD)Studies of the same condition, open and under way.
- 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
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 90 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The Hong Kong Polytechnic University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr Yvonne Han, The Hong Kong Polytechnic University
- Investigators
- Yvonne Han, PhD, Principal investigator, The Hong Kong Polytechnic University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06878326
- Sponsor's protocol ID
- HSEARS20250212003
- Status last verified
- Sep 2026
- First submitted
- 11 Mar 2025
- Last updated
- 25 Sep 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Resting-State Functional Connectivity as a Predictor of tDCS Effects in Adolescents With Autism Spectrum Disorder
- ClinicalTrials.gov ID
- NCT06878326
- Acronym / sponsor ID
- HSEARS20250212003
- Conditions
- Autism Spectrum Disorder (ASD), Transcranial Direct Current Stimulation (tDCS), Electroencephalography
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 90 participants (estimated)
- Lead sponsor
- The Hong Kong Polytechnic UniversityUniversity, hospital or other
- Study start
- 1 Sep 2025 (actual)
- Primary completion
- Apr 2027 (estimated)
- Study completion
- Apr 2027 (estimated)
- First posted
- 14 Mar 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.
Background: Transcranial Direct Current Stimulation (tDCS) is a form of non-invasive brain stimulation that has aroused increased interests in the past decade. Not only that it is transient with little side-effects, and can be well-tolerated by children, it is also affordable and readily accessible, making it an appealing treatment option for autism spectrum disorder (ASD).
Objective: (1) To evaluate the therapeutic effects of tDCS on improving cognitive function in patients with ASD, (2) to better understand the neural mechanisms underlying the neuromodulation effects of tDCS in patients with ASD, and (3) to determine whether resting-state functional connectivity measures can predict the therapeutic effects of active tDCS in individuals with ASD.
Methods: To assess the therapeutic effects and neural mechanisms of tDCS, 90 adolescents with ASD (age 12-22 years) will receive three stimulation conditions: cathodal tDCS of the left DLPFC, anodal tDCS of the left DLPFC and sham-tDCS with at least a week apart each time. During the active tDCS or sham-tDCS condition, the participants will be administered a computerized test battery (Cambridge Neuropsychological Test Automated Battery, CANTAB®) to evaluate their cognitive function. EEG before and after the tDCS to evaluate the tDCS-induced alteration in their neural activity and functional connectivity.
Hypothesis: Drawing together the different evidence linking ASD with cortical hyper-excitability and disordered neural connectivity, as reviewed previously, the investigators hypothesize that, relative to a sham-tDCS condition, active cathodal (inhibitory) and anodal (excitatory) tDCS over the left DLPRC will induce stimulation-linked facilitation of learning and resultant improvement of cognitive functioning in patients with ASD.
In addition to the therapeutic effects of tDCS, enhanced neural connectivity, as indexed by altered level EEG theta coherence in patients with ASD, will mediate the beneficial effects of tDCS, relative to sham tDCS, on improvements in cognitive function. Moreover, resting-state functional connectivity will moderate the beneficial effects of active tDCS on cognitive function, relative to sham tDCS, such that participants with greater pre-treatment resting state functional connectively will evidence greater/less response to tDCS, relative to participants receiving sham tDCS.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Cathodal active tDCS | Experimental | Device: tDCSFor cathodal tDCS condition, participants will receive cathodal stimulation on the dorsolateral prefrontal cortex with ramp up and ramp down mode for 10 seconds, eliciting a tingling sensation on the scalp that fades over seconds. Following that, a twenty-minute executive functional task will be initiated five minutes subsequent to the stimulation mode, and the stimulation will be terminated when the task ends. |
| Anodal active tDCS | Experimental | Device: tDCSFor anodal tDCS condition, participants will receive anodal stimulation on the dorsolateral prefrontal cortex with ramp up and ramp down mode for 10 seconds, eliciting a tingling sensation on the scalp that fades over seconds. Following that, a twenty-minute executive functional task will be initiated five minutes subsequent to the stimulation mode, and the stimulation will be terminated when the task ends. |
| Sham tDCS | Sham comparator | Device: tDCSFor sham-tDCS condition, participants will receive initial stimulation with ramp up and ramp down mode for 30 seconds, eliciting a tingling sensation on the scalp then it will be discontinued. Participant will also receive the twenty-minute executive functional task five minutes subsequent to the stimulation mode. |
Who may qualify
- Ages
- 12 to 22 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (3 listed)
- being 12-22 years old
- diagnosed with ASD given by registered psychiatrists or clinical psychologists according to the Diagnostic and Statistical Manual of Mental Disorders-5th Edition (DSM-5) criteria of ASD
- able to communicate in Chinese
Key exclusion criteria (3 listed)
- without a confirmed diagnosis from the clinical psychologist
- history of other neurological and psychiatric disorders and head trauma
- on psychiatric medication
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 |
|---|---|---|
| tDCSParticipant will receive three stimulation conditions: cathodal tDCS of the left DLPFC, anodal tDCS of the left DLPFC and sham-tDCS. The order of the conditions will be randomized and counterbalanced across participants, and the three stimulation conditions will be administered at least a week apart to avoid carry-over effects. The tDCS session will last for 20 minutes. | Device | Anodal active tDCS, Cathodal active tDCS, Sham tDCS |
Primary outcome
Change in CANTAB® cognitive test - Reaction Time (RTI)
Time frame: During each stimulation session, last around 3mins
RTI assesses motor and mental response speeds, reaction time, response accuracy and impulsivity. It consists of 30 trials with five potential targets and requires participants to make flexible responses as fast as possible to the target stimulus (shown in yellow). Specifically, movement and reaction time will be measured, where shorter duration reflects faster processing speed.
Change in CANTAB® cognitive test - Spatial Working Memory (SWM)
Time frame: During each stimulation session, last around 6mins
SWM assesses retention and manipulation of visuospatial information. The participant should find one yellow "token" in each of a number of boxes and use them to fill up an empty column on the right of the screen by selecting the boxes and using a process of elimination. Error selecting boxes that have already been found to be empty and revisiting boxes which have already been found to contain a token will be measured.
Change in CANTAB® cognitive test - Multitasking Test (MTT): Response Latencies
Time frame: During each stimulation session, last around 8mins
MTT assesses the ability to resolve the interference of task-irrelevant information (stroop-like effect). The test displays an arrow which can appear on either the left or right side of the screen and can point to either the left or right side. In each trial, participants are presented with a cue that indicates which button to press according to two different rules. And the rules that participants have to follow may change from trial to trial in a randomized order. Participant's response latencies will be measured.
Change in CANTAB® cognitive test - Multitasking Test (MTT): Error Scores
Time frame: During each stimulation session, last around 8mins
MTT assesses the ability to resolve the interference of task-irrelevant information (stroop-like effect). The test displays an arrow which can appear on either the left or right side of the screen and can point to either the left or right side. In each trial, participants are presented with a cue that indicates which button to press according to two different rules. And the rules that participants have to follow may change from trial to trial in a randomized order. Participant's error scores will be measured.
Changes in EEG theta coherence
Time frame: Before tDCS session, Right after tDCS session (2 timepoints, up to 20 minutes)
Each participant will be tested individually to collect EEG data. The participants' eyes-open resting condition will be assessed by EEG for 5 minutes, before and after the tDCS to evaluate the tDCS-induced alteration in their neural activity and functional connectivity. Raw data will be processed with the EEGLAB Toolbox using MATLAB® R2019a. Data from 19 electrodes will be used for analysis.
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 25 Sep 2026.
Related trials for Autism Spectrum Disorder (ASD)
Recruiting
Strategies for Toddler ASD With Remote-therapy (STAR) Model for ASD
Autism Spectrum Disorder, Therapy
Recruiting
Smith Magenis Syndrome and Autism Spectrum Disorders
Smith-Magenis Syndrome, Autism Spectrum Disorder
Active, not recruitingPhase 1
Psilocybin for Treatment-Resistant Depression in Autism
Treatment Resistant Depression, Autism Spectrum Disorder
RecruitingPhase 2
TRIal of PPF3 vs. PlaCEbo in the TReatment of Children and AdolescenTs With NeurOdeveloPmental DisorderS
Autism Disorder
Not yet recruitingObservational study
EEG As a Genetic Selection Lever in Autism Spectrum Disorder
Autism Spectrum Disorder (ASD
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.
Yvonne Han, PhD principal investigator
The Hong Kong Polytechnic University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing tDCS in people with Autism Spectrum Disorder (ASD) and Transcranial Direct Current Stimulation (tDCS), run by The Hong Kong Polytechnic University at 1 site in Hong Kong.
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 3 inclusion and 3 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 25 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 Hong Kong. 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 Yvonne Han, PhD (+852 2766 7578, yvonne.han@polyu.edu.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in CANTAB® cognitive test - Reaction Time (RTI) (time frame: During each stimulation session, last around 3mins). The study lists 5 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 25 Sep 2026.