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

NCT ID: NCT06878326

Last Updated: 2025-09-24

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 90 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-09-01
• Study Completion Date: 2027-04-30

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

Cathodal active tDCS

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.

Group Type: EXPERIMENTAL

tDCS

Intervention Type: 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

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.

Group Type: EXPERIMENTAL

tDCS

Intervention Type: 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.

Sham tDCS

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.

Group Type: SHAM_COMPARATOR

tDCS

Intervention Type: 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.

Interventions

tDCS

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.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• 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

Exclusion Criteria

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

• Minimum Eligible Age: 12 Years
• Maximum Eligible Age: 22 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

The Hong Kong Polytechnic University

OTHER

Sponsor Role: lead

Responsible Party

Dr Yvonne Han

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Yvonne Han, PhD

Role: PRINCIPAL_INVESTIGATOR

The Hong Kong Polytechnic University

Locations

The Hong Kong Polytechnic University

Hung Hom, Kowloon, Hong Kong

Site Status: RECRUITING

Countries

Hong Kong

Central Contacts

Yvonne Han, PhD

Role: CONTACT

yvonne.han@polyu.edu.hk

+852 2766 7578

Facility Contacts

Yvonne Han, PhD

Role: primary

+852 2766 7578

Other Identifiers

HSEARS20250212003

Identifier Type: -

Identifier Source: org_study_id