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

Study Overview
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Brief Summary
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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 CAARS 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.

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

Conditions
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Transcranial Direct Current Stimulation

Intervention / Treatment
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* Device: Transcranial Direct Current Stimulation
* Device: Sham


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria:Participation criteria for healthy participants Right hand dominance. No psychiatric nor neural diagnosis. Participants must be able to comprehend the study's procedure and sign an informed consent. Participation criteria for ADHD diagnosed participants ADHD diagnosis (according to DSM V). Right hand dominance. Participants must be able to comprehend the study's procedure and sign an informed consent. Participants who regularly use Methylphenidate will be required to avoid the medication for 24 hours prior to study and 12 hours post study. - Exclusion Criteria: a. Other psychiatric diagnoses (additional to ADHD). b. Drug use (excluding Methylphenidate). c. Neurological disorders. d. Pacemaker, Insulin pump

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ADHD tDCS<br> | Device: Transcranial Direct Current Stimulation<br>* 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.<br>|
| Sham Comparator: ADHD Sham<br> | Device: Sham<br>* 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.<br>|
| Experimental: Healthy control tDCS<br> | Device: Transcranial Direct Current Stimulation<br>* 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.<br>|
| Sham Comparator: Healthy control Sham<br> | Device: Sham<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| N-back | improved working memory: increase in Hit rate | through study completion, about six months | 
| Stroop | improved interference control: shorter RTs, increase in correct responses | through study completion, about six months | 
| Stop-signal | improved response inhibition: shorter RTs | through study completion, about six months | 
| Time Reproduction task | improved time perception: increased accuracy | through study completion, about six months | 
| Continuous Performance Task | improved continuous concentration: shorter RT's, decrease in errors | through study completion, about six months | 
| Navon task | improved accuracy, shorter RT's | through study completion, about six months | 

Secondary Outcome Measures

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