Effects of Transcranial Direct Current Stimulation (tDCS) on Motor Function in Schizophrenia Patients and Individuals at Risk for Psychotic Onset

Study Overview
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Brief Summary
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The purposes of this research are to investigate (1) if schizophrenia patients and at-risk individuals present bradykinesia and dyskinesia and (2) if tDCS improves motor performance in schizophrenia patients and at-risk individuals. The first hypothesis is that both schizophrenia patients and at-risk individuals show bradykinesia and dyskinesia, and the motor symptoms are more severe in the former than the latter. The second hypothesis is that tDCS improves motor performance in schizophrenia patients and at-risk cases.

Official Title
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Effects of Transcranial Direct Current Stimulation (tDCS) on Motor Function in Schizophrenia Patients and Individuals at Risk for Psychotic Onset

Conditions
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Schizophrenia, Psychosis, Parkinsonism, Dyskinesias

Intervention / Treatment
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* Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria for schizophrenia patients: a diagnosis of schizophrenia without other psychiatric diseases having stable psychotic symptoms a score of 22 or above in Hong Kong version Montreal Cognitive Assessment having no neurological diseases and no medical conditions that affect motor performance No Exclusion Criteria. Inclusion Criteria for at-risk individuals: a score of nine or above in the Chinese version of the 16-item Prodromal Questionnaire (CPQ-16) a score of 22 or above in Hong Kong version Montreal Cognitive Assessment having no diagnosis of psychiatric diseases having no neurological diseases and no medical conditions that affect motor performance No Exclusion Criteria. Inclusion Criteria for healthy controls: a score less than nine in CPQ-16 a score of 22 or above in Hong Kong version Montreal Cognitive Assessment having no diagnosis of psychiatric diseases having no neurological diseases and no medical conditions that affect motor performance. No Exclusion Criteria.

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 65 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
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: schizophrenia- tDCS<br> | Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)<br>* Transcranial direct current stimulation (tDCS) is a non-invasive intervention, which applies low-amplitude direct electric currents to the brain through scalp electrodes. The real (2mA) or sham tDCS intervention will be given for a total of eight sessions in four weeks with 20 minutes per session.<br>|
| Sham Comparator: schizophrenia- sham<br> | Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)<br>* Transcranial direct current stimulation (tDCS) is a non-invasive intervention, which applies low-amplitude direct electric currents to the brain through scalp electrodes. The real (2mA) or sham tDCS intervention will be given for a total of eight sessions in four weeks with 20 minutes per session.<br>|
| Experimental: at risk- tDCS<br> | Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)<br>* Transcranial direct current stimulation (tDCS) is a non-invasive intervention, which applies low-amplitude direct electric currents to the brain through scalp electrodes. The real (2mA) or sham tDCS intervention will be given for a total of eight sessions in four weeks with 20 minutes per session.<br>|
| Sham Comparator: at risk- sham<br> | Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)<br>* Transcranial direct current stimulation (tDCS) is a non-invasive intervention, which applies low-amplitude direct electric currents to the brain through scalp electrodes. The real (2mA) or sham tDCS intervention will be given for a total of eight sessions in four weeks with 20 minutes per session.<br>|
| Experimental: healthy controls for schizophrenia- tDCS<br> | Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)<br>* Transcranial direct current stimulation (tDCS) is a non-invasive intervention, which applies low-amplitude direct electric currents to the brain through scalp electrodes. The real (2mA) or sham tDCS intervention will be given for a total of eight sessions in four weeks with 20 minutes per session.<br>|
| Sham Comparator: healthy controls for schizophrenia- sham<br> | Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)<br>* Transcranial direct current stimulation (tDCS) is a non-invasive intervention, which applies low-amplitude direct electric currents to the brain through scalp electrodes. The real (2mA) or sham tDCS intervention will be given for a total of eight sessions in four weeks with 20 minutes per session.<br>|
| Experimental: healthy controls for at risk- tDCS<br> | Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)<br>* Transcranial direct current stimulation (tDCS) is a non-invasive intervention, which applies low-amplitude direct electric currents to the brain through scalp electrodes. The real (2mA) or sham tDCS intervention will be given for a total of eight sessions in four weeks with 20 minutes per session.<br>|
| Sham Comparator: healthy controls for at risk- sham<br> | Device: Transcranial direct current stimulation device (Soterix Medical, New York, NY)<br>* Transcranial direct current stimulation (tDCS) is a non-invasive intervention, which applies low-amplitude direct electric currents to the brain through scalp electrodes. The real (2mA) or sham tDCS intervention will be given for a total of eight sessions in four weeks with 20 minutes per session.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Motion analysis by using an eight-camera motion capture system (VICON; Oxford Metrics Group, Oxford, UK) | normalized movement time (representing severity of parkinsonism). Unit: second/mm | Within one week right before the 1st session of tDCS | 
| Motion analysis by using an eight-camera motion capture system (VICON; Oxford Metrics Group, Oxford, UK) | normalized movement time (representing severity of parkinsonism). Unit: second/mm | Within one week right after the 8th (last) session of tDCS | 
| Motion analysis by using an eight-camera motion capture system (VICON; Oxford Metrics Group, Oxford, UK) | normalized number of movement units (representing severity of dyskinesia). Unit: units/mm | Within one week right before the 1st session of tDCS | 
| Motion analysis by using an eight-camera motion capture system (VICON; Oxford Metrics Group, Oxford, UK) | normalized number of movement units (representing severity of dyskinesia). Unit: units/mm | Within one week right after the 8th (last) session of tDCS |