A Dose-Response Study of the Cognitive and Physiological Effects of tDCS to the DLPFC

Study Overview
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Brief Summary
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To determine the cognitive and neurophysiological dose-response relationships of anodal tDCS to the left DLPFC as a function of absolute current intensity, individualized E-field intensity, and stimulation duration.

Detailed Description
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To determine the cognitive and neurophysiological dose-response relationships of anodal tDCS to the left DLPFC as a function of absolute current intensity, individualized E-field intensity, and stimulation duration.

Official Title
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A Dose-Response Study of the Cognitive and Physiological Effects of tDCS to the DLPFC

Conditions
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Attention Deficit Hyperactivity Disorder

Intervention / Treatment
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* Device: Transcranial Direct Current Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria (Patients) Male and female outpatients 18-55 years of age A diagnosis of ADD/ADHD or meeting the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. Patient will be either off stimulant medications or, if undergoing treatment with stimulants, will be asked to discontinue two days prior to the experiment, under physician-guided protocol, and allowed to resume afterwards. Subjects may resume stimulant use between the two study visits so long as they discontinue use two days prior to the second study visit. If fatigue is problematic in subjects discontinuing medication, they will be allowed to continue with the study if they are able to follow the suggested taper plan (50% of the dose day one, 25% dose day 2, stop day of visit (day 3)). If on non-stimulant medications, dose must have been stable for at least 4 weeks. Exclusion Criteria (Patients) Contraindication to tDCS: history or epilepsy, metallic implants in the head and neck, brain stimulators, vagus nerve stimulators, VP shunt, pacemakers, pregnancy. Active substance dependence (except for tobacco). Pregnant or nursing females. Inability to participate in testing procedures. Inclusion Criteria (Healthy Control) 1. Male and female outpatients 18-55 years of age Exclusion Criteria (Healthy Control) Diagnosis of psychiatric of neurological disorder Ongoing treatment with any psychotropic medications. Contraindication to tDCS: history or epilepsy, metallic implants in the head and neck, brain stimulators, vagus nerve stimulators, VP shunt, pacemakers, pregnancy. Active substance dependence (except for tobacco). Pregnant or nursing females. Inability to participate in testing procedures.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: ADHD<br>Patients with ADHD. | Device: Transcranial Direct Current Stimulation<br>* In tDCS, electrodes are applied on the scalp to transmit direct current at low current amplitudes.<br>|
| Other: Healthy Control<br>Volunteers without Neuropsychiatric Disorders. | Device: Transcranial Direct Current Stimulation<br>* In tDCS, electrodes are applied on the scalp to transmit direct current at low current amplitudes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Accuracy and Reaction Time in Attention and Working Memory | Measured using Eriksen Flanker Task (EFT) | Change Before and After Stimulation on Each of the Four Visits, Average of 2-6 Weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amplitude of Electroencephalogram (EEG) Event Related Potentials | Measure of amplitude related to stimulus | Change Before and After Stimulation on Each of the Four Visits, Average of 2-6 Weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Transcranial Direct Current Stimulation