tDCS in Adults With ASD and/or ADHD Without Intellectual Disability

Ensayo clínico Fase 1 de tDCS en Adultos Con TEA y/o TDAH Sin Discapacidad Intelectual

The goal of this clinical trial is to learn about the safety and tolerability of transcranial direct current stimulation (tDCS) combined with cognitive training in adults with Autism Spectrum Disorder (ASD) and/or Attention-Deficit/Hyperactivity Disorder (ADHD).

The main question it aims to answer is:

Is tDCS safe and well-tolerated in adults with ASD and/or ADHD?

Researchers will compare active tDCS to a sham (placebo-like) stimulation to evaluate safety and tolerability.

Participants will:

Receive either active or sham tDCS for 20 minutes daily over 10 consecutive workdays

Undergo stimulation with the anode placed at F3 and the cathode at Fp2

Complete daily cognitive training exercises using the NeuronUP platform during stimulation

Attend baseline and follow-up assessments to monitor for any side effects or discomfort related to the intervention

Study Overview

• Status: Completed
• Conditions: Autism Spectrum Disorder; Attention Deficit Disorder With Hyperactivity
• Intervention / Treatment: Device: Transcranial Direct Current Stimulation - Active; Behavioral: Cognitive Training; Device: Transcranial Direct Current Stimulation - Sham

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Barcelona, Spain, 08035
    • Hospital Universitari Vall d'Hebron

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Adults aged 18 to 55 years

Clinical diagnosis of Autism Spectrum Disorder (ASD) and/or Attention-Deficit/Hyperactivity Disorder (ADHD) confirmed via medical records or structured clinical interview

Able to provide informed consent

Fluent in the language used for assessments and cognitive training tasks

Stable medication regimen (if applicable) for at least 4 weeks prior to enrollment

Willing and able to attend 10 consecutive weekday sessions and follow-up assessment

Exclusion Criteria:

History of epilepsy, seizures, or significant neurological disorder (e.g., traumatic brain injury, stroke)

Current diagnosis of psychotic disorder or bipolar disorder

Presence of metal implants in the head (excluding dental work), pacemaker, or other contraindications to tDCS

Current substance use disorder (within past 6 months)

Pregnant or planning to become pregnant during the study period

Participation in another intervention study within the last 30 days

Any condition that, in the opinion of the investigators, may make participation unsafe or interfere with study procedures

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Active tDCS + Cognitive Training; Participants in this arm will receive anodal transcranial direct current stimulation (tDCS) at 2 mA for 20 minutes per session over 10 consecutive workdays. The anode will be placed over the left dorsolateral prefrontal cortex (F3) and the cathode over the right frontopolar cortex (Fp2) using the 10-20 EEG system. Stimulation will be administered concurrently with cognitive training using the NeuronUP platform, which includes tasks targeting attention, memory, and executive function.	Device: Transcranial Direct Current Stimulation - Active; This intervention involves non-invasive brain stimulation using transcranial direct current stimulation (tDCS) delivered via saline-soaked sponge electrodes. The anode is placed at F3 (left dorsolateral prefrontal cortex) and the cathode at Fp2 (right frontopolar cortex), according to the international 10-20 EEG system. A 2 mA current is applied for 20 minutes per session, administered once daily on 10 consecutive workdays. During stimulation, participants engage in cognitive training using the NeuronUP platform, which provides structured, interactive tasks designed to train executive function, attention, and working memory. This combination aims to enhance neural plasticity by pairing neuromodulation with cognitive engagement.; Behavioral: Cognitive Training; The cognitive training intervention in this study is delivered through NeuronUP, a digital platform offering evidence-based cognitive stimulation activities. This intervention targets core cognitive domains such as working memory, attention, and executive function through personalized, interactive tasks. What distinguishes this approach is NeuronUP's extensive library of over 10,000 activities, its ability to tailor difficulty levels in real time based on individual performance, and the inclusion of functional tasks that mirror real-life scenarios. Unlike other interventions, NeuronUP also enables therapist-guided customization, allowing for individualized treatment plans that evolve with participant progress, ensuring both relevance and ecological validity.
Sham Comparator: Sham tDCS + Cognitive Training; Participants in this arm will undergo the same setup and procedures as the active tDCS group but will receive sham stimulation, which mimics the sensation of tDCS without delivering current beyond the initial ramp-up/down. They will also complete cognitive training with the NeuronUP platform during each session.	Behavioral: Cognitive Training; The cognitive training intervention in this study is delivered through NeuronUP, a digital platform offering evidence-based cognitive stimulation activities. This intervention targets core cognitive domains such as working memory, attention, and executive function through personalized, interactive tasks. What distinguishes this approach is NeuronUP's extensive library of over 10,000 activities, its ability to tailor difficulty levels in real time based on individual performance, and the inclusion of functional tasks that mirror real-life scenarios. Unlike other interventions, NeuronUP also enables therapist-guided customization, allowing for individualized treatment plans that evolve with participant progress, ensuring both relevance and ecological validity.; Device: Transcranial Direct Current Stimulation - Sham; The sham condition mimics the active setup but delivers only brief ramp-up/down stimulation, producing the initial sensation without sustained current.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability]	Participants will be monitored for adverse events, side effects (e.g., headache, skin irritation, fatigue), and dropout rates. This will be assessed through participant self-report, clinician observation, and standardized side effect checklists administered during and after each session. The outcome will help determine whether daily tDCS paired with cognitive training is safe and acceptable for adults with ASD and/or ADHD.	Throughout the 10-day intervention period and at follow-up (up to 2 weeks post-intervention)

Collaborators and Investigators

• Sponsor: Hospital Universitari Vall d'Hebron Research Institute

Study record dates

Study Major Dates

• Study Start (Actual): November 7, 2022
• Primary Completion (Actual): January 19, 2024
• Study Completion (Actual): January 19, 2024

Study Registration Dates

• First Submitted: April 8, 2025
• First Submitted That Met QC Criteria: April 23, 2025
• First Posted (Actual): April 27, 2025

Study Record Updates

• Last Update Posted (Actual): August 1, 2025
• Last Update Submitted That Met QC Criteria: July 29, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: autism; tdcs; adhd
• Additional Relevant MeSH Terms: Mental Disorders; Neurodevelopmental Disorders; Child Development Disorders, Pervasive; Attention Deficit and Disruptive Behavior Disorders; Autism Spectrum Disorder; Attention Deficit Disorder with Hyperactivity
• Other Study ID Numbers: PR (AG) 218_2022

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No