The Effect of tDCS on Schizophrenia With Negative Symptoms

Study Overview
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Brief Summary
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The investigators conducted a randomized controlled trial to reveal the effect of tDCS on negative symptoms in patients with schizophrenia and its underlying mechanism using the neuroimaging and electrophysiology.

Detailed Description
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The project will investigate the use of a novel technique, transcranial direct current stimulation (tDCS) in the treatment of patients with schizophrenia. tDCS permit the application of an extremely weak continuous electrical current to the brain through an anode and a cathode applied on the scalp. Anodal stimulation appears to increase brain activity whereas cathodal stimulation has the opposite effect. Using anodal and cathodal tDCS the investigators aimed to treat negative symptoms of schizophrenia. The investigators plan to apply tDCS such that it can simultaneously increased activity in the frontal brain areas and reduce activity over temporoparietal cortex, 2 areas involved in the physiopathology of the disease. Real active stimulation will be compare to a sham condition in 44 patients (22 in each group). 44 patients will be included in Seoul National University Hospital

Official Title
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Clinical Trials for Neuroimaging and Electrophysiology in Schizophrenic Patients With Negative Symptoms Using Transcranial Direct Current Stimulation

Conditions
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Schizophrenia

Intervention / Treatment
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* Device: tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: DSM-IV Schizophrenia 1 or more items of Negative symptom score in PANSS > 5 Exclusion Criteria: presences of neurological disorder or history IQ < 70 presence of severe personality disorders presence of substance use disorder (except nicotin) pregnancy presence of severe medical condition or disorders

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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
Interventional Model Description: Randomized controlled trial 1 arm is active tDCS and 1 arm is sham tDCS
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: actual tDCS<br>2mA direct current, 20 minutes per session, 2 sessions per day with at least 3hours interval between sessions, a total of 10 tDCS sessions | Device: tDCS<br>* Transcranial direct current stimulation (tDCS) is a form of neurostimulation that uses constant, low direct current delivered via electrodes on the head. It can be contrasted with cranial electrotherapy stimulation, which generally uses alternating current the same way<br>|
| Active Comparator: sham tDCS<br>sham direct current, 20 minutes per session, 2 sessions per day with at least 3hours interval between sessions, a total of 10 tDCS sessions | Device: tDCS<br>* Transcranial direct current stimulation (tDCS) is a form of neurostimulation that uses constant, low direct current delivered via electrodes on the head. It can be contrasted with cranial electrotherapy stimulation, which generally uses alternating current the same way<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Positive and Negative Syndrome Scale (PANSS) | changes in psychopathology To assess a patient using PANSS, an approximately 45-minute clinical interview is conducted. The patient is rated from 1 to 7 on 30 different symptoms based on the interview as well as reports of family members or primary care hospital workers | approximately 2 weeks (baseline and 2 weeks followups) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Clinical Assessment Interview for Negative Symptoms (CAINS) | changes in psychopathology The CAINS is a clinical rating scale for negative symptoms with potent and clear treatment targets for the next generation of pharmacological and psychosocial treatments. It rangs between 0 to 52 | approximately 2 weeks (baseline and 2 weeks followups) | 
| Electroencephalography - resting | changes in lagged phase synchronization and microstate connectivity | approximately 2 weeks (baseline and 2 weeks followups) | 
| Electroencephalography - P300 | changes in P300 | approximately 2 weeks (baseline and 2 weeks followups) | 
| Electroencephalography - MMN | changes in MMN | approximately 2 weeks (baseline and 2 weeks followups) | 
| Electroencephalography - ERN | changes in ERN | approximately 2 weeks (baseline and 2 weeks followups) | 
| MRI - grey matter volume | change in grey matter volume | approximately 2 weeks (baseline and 2 weeks followups) | 
| MRI - cortical thickness | change in cortical thickness | approximately 2 weeks (baseline and 2 weeks followups) | 
| MRI - cortical surface area | changes in MRI - cortical thickness | approximately 2 weeks (baseline and 2 weeks followups) | 
| MRI - cortical gyrification | changes in cortical gyrification | approximately 2 weeks (baseline and 2 weeks followups) | 
| DTI - mean diffusivity (MD) | changes in MD | approximately 2 weeks (baseline and 2 weeks followups) | 
| DTI - axial diffusivity (AD) | changes in AD | approximately 2 weeks (baseline and 2 weeks followups) | 
| DTI - radial diffusivity (RD) | changes in RD | approximately 2 weeks (baseline and 2 weeks followups) | 
| DTI - fractional anisotropy (FA) | changes in FA | approximately 2 weeks (baseline and 2 weeks followups) | 
| MRI - rsfMRI | change in BOLD signals | approximately 2 weeks (baseline and 2 weeks followups) | 
| MRI - MRS | Changes in concentration of N-Acetyl Aspartate, Creatin, Choline, Myoinositol, Glutamate, Glutamine, GABA metabolite concentration change with treatment | approximately 2 weeks (baseline and 2 weeks followups) | 
| fNIRS | change in level of the Oxy-Hemoglobin | approximately 2 weeks (baseline and 2 weeks followups) | 
| Korean Wechsler Adult Intelligence Scale (K-WAIS) | baseline total Intelligence quotient value | baseline | 
| Spatial Working Memory | changes in the spatial working memory ability | approximately 2 weeks (baseline and 2 weeks followups) | 
| California Verbal Learning Test | changes in verbal learning ability | approximately 2 weeks (baseline and 2 weeks followups) | 
| Letter/Category fluency test | changes in fluency ability | approximately 2 weeks (baseline and 2 weeks followups) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tDCS, Schizophrenia, negative symptoms