Efficacy of Transcranial Direct Current Stimulation (tDCS) in the Treatment of Adult Attention-Deficit/Hyperactivity Disorder (ADHD) (TDACS)

Efficacy of Transcranial Direct Current Stimulation (tDCS) in the Treatment of Adult Attention-Deficit/Hyperactivity Disorder (ADHD): A Randomized Double-Blind Controlled Trial

Efficacy of Transcranial Direct Current Stimulation (tDCS) in the Treatment of Adult Attention-Deficit/Hyperactivity Disorder (ADHD): A Randomized Double-Blind Controlled Trial

Study Overview

• Status: Not yet recruiting
• Conditions: Attention Deficit/Hyperactivity Disorder(ADHD)
• Intervention / Treatment: Other: Transcranial direct current stimulation (tDCS)

Detailed Description

Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by attentional difficulties and/or hyperactivity-impulsivity (American Psychiatric Association, 2013). Its treatment is primarily based on a multimodal approach, with first-line pharmacological management using methylphenidate (Ritalin®, Medikinet®, etc.).

However, given the limitations of pharmacological treatments (side effects, contraindications, and risks of misuse), alternative approaches such as transcranial direct current stimulation (tDCS) are generating increasing interest.

tDCS is a non-invasive, safe, and low-cost neuromodulation technique that delivers a low-intensity electrical current through electrodes placed on the scalp. It is well tolerated, with mild and transient adverse effects (tingling sensations, local skin redness, mild fatigue), making it a particularly safe approach. Its low cost and ease of use allow for broad accessibility, including in resource-limited healthcare settings.

In ADHD, tDCS targets the left dorsolateral prefrontal cortex, a key region involved in attention and executive functions. Early studies have reported encouraging results in terms of both efficacy and tolerability, particularly when combined with psychotherapeutic interventions.

The aim of this study is to evaluate the efficacy of tDCS in patients with ADHD.

The findings will support the potential future integration of tDCS into the management of ADHD resistant to conventional treatments.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adult patient aged 18 to 60 years inclusive
• Patient diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD), combined or predominantly inattentive presentation, previously established by a healthcare professional
• Patients must be registered in the active caseload of the Adult Neurodevelopmental Disorders Unit (STNDA)
• Stable psychotropic medication regimen for at least four weeks prior to inclusion, in terms of both molecule and dosage, particularly for methylphenidate, or no current psychotropic treatment. Medication must remain unchanged throughout study participation, unless medically justified changes are required
• Patient with a cognitive status deemed sufficient by the unit's referring psychiatrist to ensure appropriate completion of the scales and tests included in the protocol
• Free, informed, and written consent

Exclusion Criteria:

•General condition impairment (severe fatigue or marked weakness, convalescence after an acute illness or surgery, or recent alcohol consumption)

Psychiatric and neurological disorders

• Diagnosis of Autism Spectrum Disorder (ASD)
• Diagnosis of personality disorder (Cluster A, B, C, or other), according to DSM-5-TR
• Diagnosis of schizophrenia spectrum disorder or other psychotic disorders according to DSM-5-TR
• Diagnosis of bipolar disorder with manic episode or history of manic episodes according to DSM-5-TR
• Confirmed neurological disorder
• Epilepsy or history of epileptic seizures

Medical comorbidities

• Patient with known or suspected cardiac disease
• Patient with severe pulmonary disease
• Patient with cerebrovascular disease (e.g., stroke)

Dermatological and surgical contraindications

• Patient with scalp lesions, open wounds, or skin conditions (severe acne, herpes, burns, skin fissures)
• Patient with severe dermatitis, oozing eczema, or fragile scalp
• Patient with major surgical scars
• Patient with recent craniotomy

Implantable devices and materials

• Patient with a pacemaker or intracranial electrodes, presence of intracranial metal, or skull defects (e.g., post-craniectomy or trepanation without reconstruction)

Other criteria:

• Simultaneous participation in another non-pharmacological intervention provided in the STNDA day hospital (e.g., psychoeducation, cognitive remediation, body expression therapy, emotional regulation training)
• Patient with non-pathological ASRS screening scores (fewer than 4 of the first 6 items rated "Very often")
• Insufficient proficiency in the French language
• Patient under legal guardianship, curatorship, or judicial protection
• Pregnant or breastfeeding patient (based on clinical interview)

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
Sham Comparator: tDCS sham; The placebo (sham) treatment will follow an identical protocol in terms of session duration, frequency, and overall procedure. Stimulation will be simulated, with a brief ramp-up and ramp-down of current at the beginning and end of the session, without actual stimulation during the remainder of the session, in order to mimic the initial sensations of active tDCS.	Other: Transcranial direct current stimulation (tDCS); Repeated sessions of transcranial direct current stimulation (tDCS): 5 in-person tDCS sessions Intensity: 2.0 mA Duration: 20 minutes per session Frequency: 5 consecutive days Electrode placement: anode at F3 and cathode at F4
Experimental: tactive tDCS; Active transcranial direct current stimulation (tDCS): 2 mA stimulation for 20 minutes. Repeated sessions of transcranial direct current stimulation (tDCS): 5 in-person tDCS sessions Intensity: 2.0 mA Duration: 20 minutes per session Frequency: 5 consecutive days Electrode placement: anode at F3 and cathode at F4	Other: Transcranial direct current stimulation (tDCS); Repeated sessions of transcranial direct current stimulation (tDCS): 5 in-person tDCS sessions Intensity: 2.0 mA Duration: 20 minutes per session Frequency: 5 consecutive days Electrode placement: anode at F3 and cathode at F4

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Inattention Symptoms Assessed by the Adult ADHD Self-Report Scale (ASRS) from Baseline to Immediately After tDCS	The efficacy of tDCS will be assessed by measuring the change in inattention symptoms using the Adult ADHD Self-Report Scale (ASRS). The ASRS is a self-report questionnaire used to evaluate ADHD symptoms in adults. A decrease in the ASRS inattention score indicates an improvement in inattention symptoms.	Baseline and immediately after the last tDCS session

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Processing Speed Assessed by the WAIS-IV Coding and Symbol Search Subtests	Processing speed will be assessed using the Coding and Symbol Search subtests of the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV). Changes in scores will be compared between the active tDCS group and the sham tDCS group.	Baseline, immediately after the last tDCS session, and 6 weeks after the last tDCS session
Change in Working Memory Assessed by the WAIS-IV Digit Span Subtest	Working memory will be assessed using the Digit Span subtest of the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV). Changes in scores will be compared between the active tDCS group and the sham tDCS group.	Baseline, immediately after the last tDCS session, and 6 weeks after the last tDCS session
Change in Selective Attention Assessed by the d2-R Test of Attention	Selective attention will be assessed using the d2-R Test of Attention. Changes in attention performance scores will be compared between the active tDCS group and the sham tDCS group.	Baseline, immediately after the last tDCS session, and 6 weeks after the last tDCS session
Change in Emotional Regulation Assessed by the Difficulties in Emotion Regulation Scale - French Version (DERS-F)	Emotional regulation will be assessed using the Difficulties in Emotion Regulation Scale - French Version (DERS-F). Changes in emotional regulation scores will be compared between the active tDCS group and the sham tDCS group.	Baseline, immediately after the last tDCS session, and 6 weeks after the last tDCS session
Change in Anxiety and Depression Symptoms Assessed by the Hospital Anxiety and Depression Scale (HADS)	Anxiety and depression symptoms will be assessed using the Hospital Anxiety and Depression Scale (HADS). Changes in anxiety and depression scores will be compared between the active tDCS group and the sham tDCS group.	Baseline, immediately after the last tDCS session, and 6 weeks after the last tDCS session
Incidence of Adverse Events Related to tDCS	The safety and tolerability of tDCS will be assessed by comparing the frequency and nature of adverse events reported in the active tDCS group and the sham tDCS group.	From the first tDCS session through 6 weeks after the last tDCS session

Collaborators and Investigators

• Sponsor: Centre Hospitalier St Anne

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 10, 2026
• Study Completion (Estimated): February 20, 2028

Study Registration Dates

• First Submitted: May 21, 2026
• First Submitted That Met QC Criteria: June 11, 2026
• First Posted (Actual): June 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 17, 2026
• Last Update Submitted That Met QC Criteria: June 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: transcranial direct current stimulation (tDCS); stimulation;; Échelle ASRS
• Additional Relevant MeSH Terms: Mental Disorders; Neurodevelopmental Disorders; Attention Deficit and Disruptive Behavior Disorders; Attention Deficit Disorder with Hyperactivity; Therapeutics; Behavioral Disciplines and Activities; Electric Stimulation Therapy; Convulsive Therapy; Psychiatric Somatic Therapies; Electroshock; Psychological Techniques; Transcranial Direct Current Stimulation
• Other Study ID Numbers: 2025-A02038-41

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No