Cumulative and Booster Effects of Multisession Prefrontal Transcranial Direct Current Stimulation in Adolescents With ASD

NCT ID: NCT05492032

Last Updated: 2025-11-26

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 150 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-06-02
• Study Completion Date: 2026-12-31

Brief Summary

Autism spectrum disorder (ASD) is a pervasive and lifelong developmental disorder that currently affects 1 in 54 children. Individuals with autism are often severely impaired in communication, social skills, and cognitive functions. Particularly detrimental characteristics typical of ASD include the inability to relate to people and the display of repetitive stereotyped behaviors and uncontrollable temper outbursts over trivial changes in the environment, which often cause emotional stress for the children, their families, schools and neighborhood communities. To date, there is no cure for ASD, and the disorder remains a highly disabling condition. Recently, transcranial direct current stimulation (tDCS), a noninvasive neuromodulation technique, has shown great promise as an effective and cost-effective tool for reducing core symptoms, such as anxiety, aggression, impulsivity, and poor social communication, in patients with autism. Although the empirical findings in patients with ASD are encouraging, it remains to be determined whether these experimental data can be translated into real-world benefits. An important next step is to better understand the factors affecting the long-term efficacy of tDCS treatment - in particular, the possible risk factors associated with relapse in patients with ASD and the role of booster session tDCS as an add-on treatment to induce long-lasting neuroplastic effects in ASD.

Conditions

Transcranial Direct Current Stimulation; Autistic Spectrum Disorder; Electroencephalography; Booster Effects

Study Design

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

Study Groups

Active cathodal (inhibitory) tDCS vs. Sham-tDCS condition

Experimental group: active multisession tDCS + active booster tDCS vs Active control group: sham multisession tDCS + sham booster tDCS

To test whether active cathodal [inhibitory] tDCS over the left dlPRC will facilitate learning through stimulation and thus improve cognitive function in patients with ASD, the primary outcomes (SRS-2 scores) of the two groups at the start (T0), 1-month (T1), 3-month (T2), 6-month (T3), and at the end of study i.e. 12-months (T4) will be compared.

Group Type: EXPERIMENTAL

Active-tDCS

Intervention Type: DEVICE

For active-tDCS condition, participants will receive 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 training task will be initiated five minutes subsequent to the stimulation mode, and the stimulation will be terminated when the training task ends.

Sham-tDCS

Intervention Type: DEVICE

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. Participants will also receive the twenty-minute executive functional training task five minutes subsequent to the stimulation mode.

Cognitive training

Intervention Type: BEHAVIORAL

Participants will complete an online cognitive training program consisting of 10 consecutive daily weekday training sessions while they receive either the active or sham tDCS stimulation. Each training session will last for 20 minutes. The online cognitive training program will comprise five exercises assessing information processing speed and executive function capacities. Each exercise will take approximately 4 minutes to complete. Given many studies, across different neurological/neuropsychiatric diagnoses, especially for people with autism, it has long been established that social skills and functioning are closely related, and multiple studies have shown that executive function training can improve social functioning in autism or vice versa (i.e. social skills training improves executive functioning in autism), it is reasonable to include cognitive training in this tDCS protocol.

Active booster tDCS treatment vs. Sham booster tDCS treatment

Experimental group: active multisession tDCS + active booster tDCS vs Active control group: active multisession tDCS + sham booster tDCS

To test whether booster treatment cycles of tDCS will prolong the cognitive benefits in individuals with ASD), the primary outcome, the total SRS-2 score, and the secondary outcomes, the E/I ratio and the cognitive composite score at the start (T0), 1-month (T1), 3-month (T2), 6-month (T3), and at the end of study i.e. 12-months (T4), will be compared.

Group Type: EXPERIMENTAL

Active-tDCS

Intervention Type: DEVICE

For active-tDCS condition, participants will receive 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 training task will be initiated five minutes subsequent to the stimulation mode, and the stimulation will be terminated when the training task ends.

Sham-tDCS

Intervention Type: DEVICE

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. Participants will also receive the twenty-minute executive functional training task five minutes subsequent to the stimulation mode.

Cognitive training

Intervention Type: BEHAVIORAL

Participants will complete an online cognitive training program consisting of 10 consecutive daily weekday training sessions while they receive either the active or sham tDCS stimulation. Each training session will last for 20 minutes. The online cognitive training program will comprise five exercises assessing information processing speed and executive function capacities. Each exercise will take approximately 4 minutes to complete. Given many studies, across different neurological/neuropsychiatric diagnoses, especially for people with autism, it has long been established that social skills and functioning are closely related, and multiple studies have shown that executive function training can improve social functioning in autism or vice versa (i.e. social skills training improves executive functioning in autism), it is reasonable to include cognitive training in this tDCS protocol.

Change in EEG E/I ratios in the active tDCS vs. sham tDCS groups

Experimental group: active multisession tDCS + active booster tDCS vs Active control group: sham multisession tDCS + sham booster tDCS

To test whether enhanced neuronal network organization, as indicated by EEG E/I ratios, in patients with ASD will mediate the beneficial effects of tDCS in terms of improvements in cognitive function, measurements taken at baseline, 1-day and 1-month after tDCS treatment will be compared. The change in EEG E/I ratios in patients in the active tDCS and sham tDCS groups will be compared using E/I ratios averaged from channels Fp1, F3, and F7 to increase the signal-to-noise ratio of the EEG data and to represent the left frontal E/I ratio.

Group Type: EXPERIMENTAL

Active-tDCS

Intervention Type: DEVICE

For active-tDCS condition, participants will receive 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 training task will be initiated five minutes subsequent to the stimulation mode, and the stimulation will be terminated when the training task ends.

Sham-tDCS

Intervention Type: DEVICE

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. Participants will also receive the twenty-minute executive functional training task five minutes subsequent to the stimulation mode.

Cognitive training

Intervention Type: BEHAVIORAL

Participants will complete an online cognitive training program consisting of 10 consecutive daily weekday training sessions while they receive either the active or sham tDCS stimulation. Each training session will last for 20 minutes. The online cognitive training program will comprise five exercises assessing information processing speed and executive function capacities. Each exercise will take approximately 4 minutes to complete. Given many studies, across different neurological/neuropsychiatric diagnoses, especially for people with autism, it has long been established that social skills and functioning are closely related, and multiple studies have shown that executive function training can improve social functioning in autism or vice versa (i.e. social skills training improves executive functioning in autism), it is reasonable to include cognitive training in this tDCS protocol.

Interventions

Active-tDCS

For active-tDCS condition, participants will receive 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 training task will be initiated five minutes subsequent to the stimulation mode, and the stimulation will be terminated when the training task ends.

Intervention Type: DEVICE

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. Participants will also receive the twenty-minute executive functional training task five minutes subsequent to the stimulation mode.

Intervention Type: DEVICE

Cognitive training

Participants will complete an online cognitive training program consisting of 10 consecutive daily weekday training sessions while they receive either the active or sham tDCS stimulation. Each training session will last for 20 minutes. The online cognitive training program will comprise five exercises assessing information processing speed and executive function capacities. Each exercise will take approximately 4 minutes to complete. Given many studies, across different neurological/neuropsychiatric diagnoses, especially for people with autism, it has long been established that social skills and functioning are closely related, and multiple studies have shown that executive function training can improve social functioning in autism or vice versa (i.e. social skills training improves executive functioning in autism), it is reasonable to include cognitive training in this tDCS protocol.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Individuals who are confirmed by a clinical psychologist based on the Diagnostic and Statistical Manual of Mental Disorders-5th Ed (DSM-V) criteria of Autism spectrum disorder and structured interview with their parents or primary caregivers on their developmental history using the Autism Diagnostic Interview-Revised (ADI-R).
• Individuals with ASD who are comorbid with ADHD symptoms will be included if they were willing to abstain from the use of these medications at least 96 hours before the commencement, until the completion, of the treatment.
• In view of the fact that neuroadaptation to antipsychotics typically occurs within six months, potential participants who are prescribed antipsychotic medications will only be included if the dosage of the medication remained unchanged for six months or more before the experimental period.

Exclusion Criteria

• Individuals without a confirmed diagnosis from the clinical psychologist, with a history of other neurological and psychiatric disorders and head trauma, or on psychiatric medication will be excluded from the study.
• In view of the possibility of seizure induction by tDCS, potential ASD participants comorbid with epilepsy will be excluded.
• Potential participants comorbid with mood or anxiety disorders will also be excluded.

• Minimum Eligible Age: 12 Years
• Maximum Eligible Age: 21 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, Department of Rehabilitation Sciences

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

Melody Chan, PhD

Role: CONTACT

mei-yan-melody.chan@connect.polyu.hk

Facility Contacts

Yvonne Han, PhD

Role: primary

yvonne.han@polyu.edu.hk

27667578

Melody Chan, PhD

Role: backup

mei-yan-melody.chan@connect.polyu.hk

Other Identifiers

HSEARS20220216004-01

Identifier Type: -

Identifier Source: org_study_id