Cumulative and Booster Effects of Multisession Prefrontal tDCS in ASD Adolescents

The Hong Kong Polytechnic University

Status: Enrolling

Conditions: Electroencephalography; Autistic Spectrum Disorder; Transcranial Direct Current Stimulation

Treatments: Device: Active-tDCS; Device: Sham-tDCS

Study type: Interventional

Funder types: Other

Identifiers

NCT06272669

HSEARS20220216004

Details and patient eligibility

About

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by disturbances in communication, poor social skills, and aberrant behavior. To date, ASD has no known cure, and the disorder remains a highly disabling condition. Recently, transcranial direct-current stimulation (tDCS), a non-invasive brain stimulation technique, has shown great promise as a potentially effective and cost-effective tool for reducing the core symptoms in patients with autism, such as anxiety, aggression, impulsivity, and inattention. Although the preliminary findings in patients with ASD are encouraging, it remains to be determined whether this experimental data can translate into benefits in real life. Further studies are needed to determine the factors that can lengthen the therapeutic effects or cognitive benefits of tDCS, and to determine possible risk factors associated with relapse in patients with ASD. Booster sessions of tDCS is an important component of treatment planning and prognosis and may promote better outcomes to control for resurgence of symptoms. This study has three aims. First, the investigators aim to evaluate the therapeutic effects of tDCS on improving cognitive function in patients with ASD. Second, the investigators aim to better understand the neural mechanisms underlying the neuro-enhancing effects of tDCS in patients with ASD. Third, the investigators aim to assess the effectiveness of booster treatment cycles of tDCS for enhancing cognitive and social functions in individuals with ASD.

Enrollment: 90 estimated patients

Sex: All

Ages: 12 to 21 years old

Volunteers: No Healthy Volunteers

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).

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Triple Blind

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90 participants in 3 patient groups

Active-tDCS vs Sham-tDCS

Experimental group

Description:

During the active- and sham-tDCS conditions, the participants will receive current with ramp up and ramp down mode for 10 seconds, eliciting a tingling sensation on the scalp that fades over seconds. Following that, the tasks will be initiated five minutes subsequent to the stimulation mode and terminated prior to its end for active-tDCS condition. Whereas, the sham condition with the same placement and intensity will only receive 30s initial stimulation and then discontinue. Throughout the active / sham-tDCS condition, participants are required to sit still and focus their attention on a "+" displayed on a computer monitor during the five-minute rest. After that, they will undergo active-tDCS (1mA, 20 min) to the left DLPFC or sham stimulation over 10 sessions in 2 weeks, while performing the executive function training tasks.

Treatment:

Device: Sham-tDCS

Device: Active-tDCS

Crossover trial

Other group

Description:

Participants in the sham-tDCS group will receive 10-day active tDCS and assessments will be performed before and after the 10-tDCS session.

Treatment:

Device: Active-tDCS

Booster effect

Experimental group

Description:

All tDCS responders (\>10% reduction in SRS scores) will enrol on a 6 months follow-up phase in which they will be randomized to receive either bimonthly 20-minute booster tDCS sessions, or bimonthly 20-minute booster sham tDCS sessions for 3 months, followed by monthly 20-minute booster tDCS, monthly 20-minute booster sham tDCS, for another 3 months, with a maximum of 9 (sham) tDCS booster sessions.

Treatment:

Device: Sham-tDCS

Device: Active-tDCS