Neuromodulation in Depressed and Schizophrenic Patients - Changing MEP (Muscle Evoked Potentials) by tDCS (Transcranial Direct Current Stimulation)

Study Overview
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Brief Summary
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Muscle evoked potentials (MEP) are supposed to different in schizophrenic and depressed patients, compared to a sample of healthy volunteers. Transcranial Magnetic Stimulation (TMS)-evoked MEP are measured in all three groups at baseline and after tDCS (2 mA, 20 minutes). MEP amplitudes are supposed to normalize quickly in healthy volunteers, to stay diminished in depressed patients and to stay elevated in schizophrenic patients. These differences should disappear after regular pharmacological treatment. Outcome measures will be done in week 2 and week 4.

Official Title
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Transcranial Direct Current Stimulation (tDCS)-Boosted Changes in Muscle Evoked Potentials (MEP) in Depressed and Schizophrenic Patients Reveal Deficits in Neuromodulation

Conditions
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Schizophrenia, Depression

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patient must be in the condition to understand the patient-information, as well as the necessary examinations. He/she must be able to give a written consent. No medication at least three weeks before enrollment. Exclusion Criteria: Existence of a care/legal incapacity Existing pregnancy Severe psychiatric illness (with exception of affective disorder) Acute suicidality Drug-, medication- or alcohol dependence Dementia according to DSM IV / ICD 10-criterions Severe brain infarctus in the anamnesis Indications of structural damage of the basal ganglia or the brain stem Severe neurological disorders (e.g. M. Parkinson, epilepsy, discus-prolapse, dementia, systemic neurological illnesses, normal pressure hydrocephalus, cerebrovascular diseases, elevated intracranial pressure, in the last 6 months, polyneuropathies). Severe other medical conditions, like manifest arterial hypertonia, severe heart disease, pacemakers, respiratory failure, malignant illnesses all type, also in the history, active infectious diseases, skeletal disorders (like M. Paget, osteoporosis with spontaneous fractures, fresh fractures) Other circumstances, that speaks against a participation of the patient pinion of Medical Doctor at this study.

Ages Eligible for Study
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Minimum Age: 18 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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Decreased MEP amplitudes in depressed patients | MEP amplitudes are supposed to be lower than in healthy controls or schizophrenic patients | at baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Elevated MEP amplitudes in schizophrenic patients | MEP amplitued are supposed to be elevated in schizophrenic patients in comparison to depressed patients or healthy controls | at baseline | 
| Normalization of MEP amplitudes after drug treatment | MEP aplitued of schizophrenic patients are supposed to normalize after regular drug treatment within 4 weeks. | 4 weeks after baseline | 
| Normalization of MEP amplitudes after drug treatment | MEP aplitued of depressed patients are supposed to normalize after regular drug treatment within 4 weeks. | 4 weeks after baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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differences of Muscle evoked potentials (MEP) in psychiatric illnesses, differences in neuromodulation, normalization of neuromodulation after pharmacological treatment