tDCS Applied to the OFC: Effects on Decision-Making and Impulse Control

Study Overview
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Brief Summary
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In this study the investigators aim to assess whether transcranial direct current stimulation (tDCS; a safe and non-invasive method for modulating the activity of specific brain regions) when applied over the orbitofrontal cortex (OFC) is able to modulate decision-making and impulse control in healthy participants.

Detailed Description
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In this single-blind, three-arm and sham-controlled study, we will assess whether transcranial direct current stimulation (tDCS; a safe and non-invasive method for modulating the activity of specific brain regions) when applied over the orbitofrontal cortex (OFC) is able to modulate decision-making and impulse control in healthy volunteers. We hypothesize that tDCS applied to the OFC, in comparison to sham tDCS, will significantly enhance decision-making and impulse control. For this study we will enroll 45 healthy individuals aged 18-60 years. These individuals will be assessed with a battery of computerized tasks as well as clinician-administered and self-reported questionnaires on depression and anxiety. Assessments will be carried out before and after a single 30-minute tDCS session.

Official Title
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Modulating Decision-Making and Impulse Control With Transcranial Direct Current Stimulation (tDCS) Over the Orbitofrontal Cortex (OFC): A Randomized and Sham-Controlled Study

Conditions
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Impulsive Behavior, Suicidal Impulses

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: Men or women aged 18 to 60 years Exclusion Criteria: Presence any psychiatric and/or neurological illness Psychoactive substance abuse/dependence in the past 6 months Current use of medication(s) that might influence cognition and/or affective status Presence of an uncontrolled medical disease (e.g., cardiovascular, renal) Pregnancy and/or lactation Specific contraindication for tDCS (e.g., metallic head implant).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Left OFC Group<br>Anode applied to the left OFC and cathode applied to the right OFC | Device: Transcranial Direct Current Stimulation<br>* Anode placed over the OFC or the DLPFC and cathode placed over the occipital region<br>* Other names: tDCS, Brain Polarization;|
| Experimental: Right OFC Group<br>Anode applied to the right OFC and cathode applied to the left OFC | Device: Transcranial Direct Current Stimulation<br>* Anode placed over the OFC or the DLPFC and cathode placed over the occipital region<br>* Other names: tDCS, Brain Polarization;|
| Sham Comparator: Sham tDCS<br> | Device: Transcranial Direct Current Stimulation<br>* Anode placed over the OFC or the DLPFC and cathode placed over the occipital region<br>* Other names: tDCS, Brain Polarization;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the net score of the Iowa Gambling Task |  | Before and after a 30-minute tDCS session | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the average-adjusted number of pumps in the Balloon Analog Risk Task |  | Before and after a 30-minute tDCS session | 
| Change in the number of risky choices in the Game of Dice Task |  | Before and after a 30-minute tDCS session | 
| Change in the number of commission errors in the Continuous Performance Task |  | Before and after a 30-minute tDCS session | 
| Change in the interference index in the Stroop Color-Word Test |  | Before and after a 30-minute tDCS session | 
| Change in the stop-signal reaction time in the Stop-Signal Task |  | Before and after a 30-minute tDCS session | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Decision-making, Impulse control, Transcranial direct current stimulation, Brain stimulation, Neuromodulation, tDCS, Iowa Gambling Task, Stroop Word-Color Task