tDCS, Stress and Risk for Schizophrenia

Study Overview
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Brief Summary
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An exacerbated response to stress mediated by activation of the Hypothalamo-Pituitary-Adrenocortical (HPA) axis is thought to play an important role in the onset, worsening and relapse of schizophrenia. Subjects at risk for schizophrenia (unaffected siblings of patients) displayed an intermediate hyperreactivity to stress as compared with patients and healthy controls. Symptoms of schizophrenia can be reduced with noninvasive brain stimulation (NIBS) applied over the dorsolateral prefrontal cortex (DLPFC). Importantly, this same DLPFC NIBS protocol can modulate decision making processes and modulate biological reactivity to stress by decreasing salivary cortisol concentration in acute stress condition.

Detailed Description
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The objective of this project is to evaluate how the modulation of DLPFC activity in acute stress condition influences decision-making in unaffected siblings of patients with schizophrenia. Methods: 30 unaffected siblings of patients with schizophrenia will be enrolled and randomized into 2 groups. 15 subjects will receive active tDCS (2mA, 30 min, anode left DLPFC, cathode right DLPFC) and 15 will receive sham tDCS. tDCS procedure: There is a total of 30 minutes of stimulation at the intensity of 2mA (ramp up and ramp down: 30 sec). Sham stimulation consists in delivering 1 minute of real stimulation. The stimulation site (DLPFC) will be anatomically determined according to 10/20 EEG system (F3 & F4). This procedure is in accordance with international guidelines for safety. Safety and blinding will be assessed using specific tools at the end of the protocol. Stress paradigm: In order to induce moderate stress in humans in laboratory condition, the investigators will use the Maastricht Acute Stress Test (MAST). This test is a combination between physical (hand immersion in cold water) and cognitive (arithmetic calculation) stress. Test will start 5 minutes after the beginning of stimulation session. Decision-making paradigm: The decision-making task will be performed before and after the MAST (during the stimulation) in order to compare changes induce by stress and/or stimulation. The choose test is the Delay Discounting Task (DDT) permitting a measure of decision-making, reward seeking and impulsivity. Stress measure: Saliva samples will be collected using a Salivette®, samples will be stored frozen (- 20°C). Saliva cortisol levels will be measured by ELISA. The investigators also will measure heart rate, systolic and diastolic blood pressures at each time of saliva extraction (each 15 minutes, 1st sample at 9:00 am, please see figure 1). Anxiety will be assessed using the State-Trait Anxiety Inventory (STAI) before and after stimulation

Official Title
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Effects of Transcranial Direct Current Stimulation on Stress Reactivity and Decision Making in Unaffected Siblings of Patients With Schizophrenia

Conditions
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Schizophrenia

Intervention / Treatment
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* Device: Transcranial stimulation in direct current


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject to genetic risk of schizophrenia, related first-degree schizophrenic patient Man and woman Age between 18 and 30 years old Exclusion Criteria: Contraindications to the practice of the tDCS, for safety measure, we will use the same contraindications as the practice of the Magnetic resonance imaging Psychiatric disorder on axis I of DSM 5 Pregnant or nursing women

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

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
Interventional Model Description: In a randomized controlled double blind study, 30 subjects, first-degree relatives of schizophrenic patients, were randomly assigned to 2 groups. A group of 15 participants will receive 30 minutes of active tDCS (2mA, 30 minutes with the anode at the left DLPFC and the cathode at the right DLPFC); A group of 15 participants will receive 30 minutes of placebo stimulation. During this stimulation session, all participants will undergo a standardized stress test combining psychosocial stress and physical stress
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Transcranial stimulation in direct current(tDCS)active<br>30 minutes of active Transcranial stimulation in direct current | Device: Transcranial stimulation in direct current<br>* tDCS (2mA, 30 minutes with the anode at the left DLPFC and the cathode at the right DLPFC) active or placebo<br>|
| Placebo Comparator: Transcranial stimulation in direct current(tDCS) placebo<br>30 minutes of placebo stimulation | Device: Transcranial stimulation in direct current<br>* tDCS (2mA, 30 minutes with the anode at the left DLPFC and the cathode at the right DLPFC) active or placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cortisol | Salivary cortisol will be analyzed, using Salivette tubes | One year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Decision-making capacities | Decision-making capacities will be measured using a computerized version of the delay discounting task in which participants have to choose between 2 rewards | 6 mois | 
| electroencephalography | EEG will be acquired twice. It consists in an at rest recording of EEG 64 channels, eyes closed to measure spectral power intensities | 6 mois | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tDCS, non invasive brain stimulation