Transcranial Direct Current Stimulation (tDCS) as a Treatment for Cognitive Deficits in Schizophrenic

Study Overview
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Brief Summary
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This trial attempts to evaluate the effects of intensive transcranial direct-current stimulation (tDCS) on improving cognition in schizophrenia patients and changes in resting state brain network connectivity, especially increasing connectivity in the tasks related network, and increasing activation the DLPFC in a working memory task. Half of the participants will be randomized to tDCS group, while the other half will be randomized to receive sham tDCS.

Detailed Description
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Schizophrenia patients (SZ) show profound and persistent cognitive deficits in attention, executive processing, and verbal and visuospatial memory, which persist even after psychotic symptoms are ameliorated. Cognitive deficits may be more important in preventing functional, occupational, and social recovery in SZ than other symptom domains and are not effectively treated by current pharmacological approaches. Transcranial direct-current stimulation (tDCS) is less expensive than other modalities (e.g. repetitive transcranial magnetic stimulation; rTMS), easily available, and has a good safety profile in healthy controls (HC) and SZ. However, these prior studies did not make use of a validated measure such as the MATRICS consensus battery (MCCB), which is now established as the standard for assessing cognitive improvement in SZ. Despite these promising preliminary results, this effect of tDCS in SZ needs to be confirmed and the underlying biological mechanism elucidated. Therefore, the investigators employed MCCB to evaluate the effects on improving cognition and functional MRI to explore the underlying mechanism. Half of the participants will be randomized to tDCS group, while the other half will be randomized to receive sham tDCS. Active vs. sham treatment will be randomly using computer generated lists. Subjects and researcher-administrators of tDCS and testers or evaluators will be blind to treatment.The main cognitive outcome measure, the MCCB, will be administered at baseline and 1 day after the last tDCS session.Participants will be scanned once prior to tDCS sessions, and within one day after the 10th tDCS sessions using our Siemens 3T Verio MRI scanner.

Official Title
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Research on Transcranial Direct Current Stimulation (tDCS) as a Treatment for Cognitive Deficits in Schizophrenic

Conditions
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Schizophrenia

Intervention / Treatment
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* Device: tDCS
* Device: Sham tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects who have cognitive deficits as indicated by a score of < 85 on RBANS, and meet criteria for DSM-5 diagnosis of chronic SZ, schizoaffective disorder (SA), or schizophreniform disorder (SZF), and who are stably treated with antipsychotic medications and are not in acute exacerbation of illness symptoms. Exclusion Criteria: Patients with risk factors for an MRI scan, seizure disorder, and for women of childbearing age who are pregnant or regularly engaging in sexual activity and not regularly using an acceptable birth control method (systemic or double-barrier).

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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No

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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: tDCS group<br>The active tDCS group will be stimulated with transcranial Direct Current Stimulation (tDCS). | Device: tDCS<br>* Electrodes for tDCS will have the anode placed over the left DLPFC (F3) and the cathode over the contralateral (right) supraorbital ridge. The exact location of electrodes will be determined by the 10/20 EEG method with EEG cap. Subjects will have tDCS sessions on consecutive days (weekends and holidays excluded). The tDCS group will have 10 active or sham tDCS sessions. The active group will be stimulated with a 2 mA current for 20 minutes.<br>|
| Sham Comparator: Sham tDCS group<br>The sham tDCS group will have stimulation with sham transcranial Direct Current Stimulation (tDCS). | Device: Sham tDCS<br>* Electrodes for tDCS will have the anode placed over the left DLPFC (F3) and the cathode over the contralateral (right) supraorbital ridge. The exact location of electrodes will be determined by the 10/20 EEG method with EEG cap. Subjects will have tDCS sessions on consecutive days (weekends and holidays excluded). The sham tDCS group will have 10 active or sham tDCS sessions. The sham group will have stimulation lasting only 40 seconds though the electrodes will remain in place for 20 min.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The MATRICS Consensus Cognitive Battery (MCCB) |  | Change from Baseline MCCB through study completion, an average of 15 days | 
| Neuroimage changes in Magnetic Resonance Imaging (MRI) | Including T1, resting state functional MRI, task based functional MRI and Diffusion Tensor Imaging(DTI) | Change from Baseline MCCB through study completion, an average of 15 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The CogState: Working memory and attention |  | through study completion, an average of 15 days | 
| The Positive and Negative Syndrome Scale (PANSS) |  | Change from Baseline MCCB through study completion, an average of 15 days | 
| Side-effects of tDCS |  | through study completion, an average of 15 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tDCS, schizophrenia, cognition, fMRI