Transcranial Direct Current Stimulation (tDCS) as a Cognitive Functioning Enhancement Treatment for ADHD Patients Compared to Healthy Controls

This study will examine the possible effects of tDCS (Transcranial Direct Current Stimulation) treatment to the left DLPFC on cognitive functions which were found to be deficient amongst ADHD patients. The study will include 100 subjects, 50 of whom diagnosed with ADHD. Subjects will complete the ASRS questionnaire to measure ADHD symptoms severity. Next, subjects will complete a series of cognitive tasks, after which they will receive either tDCS treatment or a sham treatment. Finally, subjects will repeat the cognitive tasks. Later that day, a telephonic follow up will take place. ADHD symptoms will be assessed again the next day.

Study Overview

• Status: Completed
• Conditions: Transcranial Direct Current Stimulation
• Intervention / Treatment: Device: Transcranial Direct Current Stimulation; Device: Sham

• Study Type: Interventional
• Enrollment (Actual): 63
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Israel
  • Jerusalem, Israel
    • Hebrew University of Jerusalem

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:Participation criteria for healthy participants

1. Right hand dominance.
2. No psychiatric nor neural diagnosis.
3. Participants must be able to comprehend the study's procedure and sign an informed consent.

Participation criteria for ADHD diagnosed participants

1. ADHD diagnosis (according to DSM V).
2. Right hand dominance.
3. Participants must be able to comprehend the study's procedure and sign an informed consent.

4. Participants who regularly use Methylphenidate will be required to avoid the medication for 24 hours prior to study and 12 hours post study.

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Exclusion Criteria:

• a. Other psychiatric diagnoses (additional to ADHD). b. Drug use (excluding Methylphenidate). c. Neurological disorders. d. Pacemaker, Insulin pump

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ADHD tDCS	Device: Transcranial Direct Current Stimulation; To stimulate the left DLPFC, the anode electrode will be placed over F3 and the cathode will be placed over F4. Each stimulation will be applied for 20 min at 2mA intensity.
Sham Comparator: ADHD Sham	Device: Sham; For the sham treatment, stimulation will be stopped after 30 seconds. Current will be renewed five times throughout the session for 2 seconds each time, to mimic the tDCS stimulation.
Experimental: Healthy control tDCS	Device: Transcranial Direct Current Stimulation; To stimulate the left DLPFC, the anode electrode will be placed over F3 and the cathode will be placed over F4. Each stimulation will be applied for 20 min at 2mA intensity.
Sham Comparator: Healthy control Sham	Device: Sham; For the sham treatment, stimulation will be stopped after 30 seconds. Current will be renewed five times throughout the session for 2 seconds each time, to mimic the tDCS stimulation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
N-back	change in working memory: increase in hit rate	through study completion
Stroop	change in interference control: smaller interference effect	through study completion, up to 1 hour after treatment
Stop-signal	change in response inhibition: shorter SSRT	through study completion, up to 1 hour after treatment
Time Reproduction task	change in time perception: increased accuracy	through study completion, up to 1 hour after treatment
Continuous Performance Task	change in continuous concentration: increase in accuracy	through study completion, up to 1 hour after treatment
Navon task	change in accuracy, shorter RT's	through study completion, up to 1 hour after treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ADHD symptoms - CAARS questionnaire	decrease in symptoms severity	through study completion, about six months

Collaborators and Investigators

• Sponsor: Hebrew University of Jerusalem

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2021
• Primary Completion (Actual): November 22, 2022
• Study Completion (Actual): June 1, 2023

Study Registration Dates

• First Submitted: December 31, 2020
• First Submitted That Met QC Criteria: January 5, 2021
• First Posted (Actual): January 6, 2021

Study Record Updates

• Last Update Posted (Actual): March 7, 2024
• Last Update Submitted That Met QC Criteria: March 4, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: tDCS-ADHD

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