Resting-State Functional Connectivity as a Predictor of tDCS Effects in Adolescents With Autism Spectrum Disorder

NCT06878326 | Recruiting

• 1 other identifier: HSEARS20250212003
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 1

Brief 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 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.

Conditions

Autism Spectrum Disorder (ASD); Transcranial Direct Current Stimulation (tDCS); Electroencephalography

Outcome Measures

Primary Outcomes (5)

• 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.

  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.

  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.

  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.

  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.

  Before tDCS session, Right after tDCS session (2 timepoints, up to 20 minutes)

Study Arms (3)

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.

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.

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.

Device: tDCS

Interventions

tDCS DEVICE

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.

Anodal active tDCS; Cathodal active tDCS; Sham tDCS

Eligibility Criteria

• Age: 12 Years - 22 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• without a confirmed diagnosis from the clinical psychologist
• history of other neurological and psychiatric disorders and head trauma
• on psychiatric medication

Sponsors & Collaborators

• The Hong Kong Polytechnic University: lead

Study Sites (1)

The Hong Kong Polytechnic University

Hung Hom, Kowloon, Hong Kong

RECRUITING

MeSH Terms

Conditions

Autism Spectrum Disorder

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

Child Development Disorders, Pervasive; Neurodevelopmental Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Study Officials

• Yvonne Han, PhD

  The Hong Kong Polytechnic University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Yvonne Han, PhD

CONTACT

+852 2766 7578; yvonne.han@polyu.edu.hk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: March 11, 2025
• First Posted: March 14, 2025
• Study Start: September 1, 2025
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): April 1, 2027
• Last Updated: September 24, 2025

Record last verified: 2025-03

Locations

HK (1)