Impact of tDCS on Emotional Processing in Major Depression

Study Overview
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Brief Summary
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Background: transcranial direct current stimulation (tDCS) is an innovative treatment for major depression. However, its mechanisms of action are still unclear. Major depression is characterized by impaired processing of emotional information, which returns back to normal after successful antidepressant treatment. In this randomized double-blind study, the investigators aim to assess the effect of tDCS on emotional processing in major depression.

Detailed Description
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Methods: 40 subjects with major depression (20 active treatment and 20 placebo) will receive ten 30-minutes sessions of active two milliamps or sham tDCS (anode over left dorsolateral prefrontal cortex and cathode over right dorsolateral prefrontal cortex), twice a day for 5 consecutive days. Psychometric assessment of depression (MADRS,Beck Depression Inventory , CGI) and a neuropsychological assessment will be conducted before and after the treatment. A facial emotion recognition task and an attentional emotional task with measurement of eye-tracking, heart rate, respiratory frequency and skin conductance will be conducted before and after the first session, and after the last session. The investigators hypothesize that active tDCS will improve emotional processing in major depression, and that this will be observed after 1 and 10 sessions of tDCS. Conclusions: Studying the impact of transcranial direct current stimulation on emotional processing in major depression could allow to better understand its antidepressant mechanisms

Official Title
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Impact of Transcranial Direct Current Stimulation on Emotional Processing in Major Depression

Conditions
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Major Depressive Disorder

Intervention / Treatment
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* Device: transcranial direct current stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy controls: Age between 18 and 65 years Given consent. Depressed subjects: Major depressive episode (no psychotic features) according to Diagnostic ans Statistical of Mental Disorders number 5 (DSM 5.0.) Age from 18-65 Antidepressant stable for the last 4 weeks MADRS ≥ 20. Given consent Exclusion Criteria: Healthy controls: Psychiatric disorder Addiction except for tobacco addiction Ocular disease (except from refraction disorders), neurologic or cardiac disease. Neuroleptic or anticonvulsivant treatment Presence of a specific contraindication for tDCS (e.g., personal history of epilepsy, metallic head implant, cardiac pacemaker) Depressed subjects: Other psychiatric disorder except for personality disorders Ocular disease (except from refraction disorders), neurologic or cardiac disease. Neuroleptic or anticonvulsivant treatment Presence of a specific contraindication for tDCS (e.g., personal history of epilepsy, metallic head implant, cardiac pacemaker)

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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo tDCS<br>Subjects will receive 10 30-minutes sessions of sham tDCS, twice a day for 5 consecutive day. Facial emotion recognition task and attentional task with measurement of eye-tracking, heartrate, respiratory frequency and skin conductance will be conducted before and after the first session, and after the last session. | Device: transcranial direct current stimulation<br>* Subjects will receive 10 30-minutes sessions of two milliamps transcranial direct current stimulation , twice a day for 5 consecutive day. Facial emotion recognition task and attentional task with measurement of eye-tracking, heartrate, respiratory frequency and skin conductance will be conducted before and after the first session, and after the last session.<br>|
| Experimental: Active tDCS<br>receive 10 30-minutes sessions of two milliamps tDCS, twice a day for 5 consecutive day. Stimulation will be performed using an tDCS stimulator with two 7×5 cm (35 cm2) sponge electrodes soaked in a saline solution (0.9% NaCl) Anode will be placed over the left dorsolateral prefrontal cortex (F3 according to the international EEG system) and cathode over the right dorsolateral prefrontal cortex (F4 according to the international EEG system) The twice daily sessions will be separated by at least 2 hours. | Device: transcranial direct current stimulation<br>* Subjects will receive 10 30-minutes sessions of two milliamps transcranial direct current stimulation , twice a day for 5 consecutive day. Facial emotion recognition task and attentional task with measurement of eye-tracking, heartrate, respiratory frequency and skin conductance will be conducted before and after the first session, and after the last session.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of correct responses at a facial expression recognition task | A computerized facial expression recognition task was designed for the study. 240 pictures of emotional faces (8 identities, expressing anger, sadness, happiness, surprise, disgust, or fear, morphed with intensity of 20, 40, 50, 60 and 80%) are randomly displayed on a screen for 500ms. Subjects are asked to identify the emotion by answering on a keyboard. Rate of correct responses is the main outcome. During this task, eye movements are recorded by an eye-tracking device. Skin conductance, respiratory and heart rate frequency are also recorded | within 5 days after stimulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evolution of the depressive symptoms measured by MADRS | Montgomery-Asberg Depression Rating Scale is a 10-item scale to evaluate the intensity of the depressive symptoms. | an average of two weeks | 
| Performance on an attentional dot-probe task | Computerized dot-probe  attentional task designed for the study. Pairs of emotional faces (neutral/sad ou neutral/happy) are randomly presented on a screen for 1000ms. Then, a probe is presented during 1100ms.subjects are asked to indicate a which side the probe approved During this task, eye movements are recorded by an eye-tracking device. Total time spent on Region of Interest (sad, happy or neutral face) is measured. Skin conductance, respiratory and heart rate frequency are also recorded. | within 5 days after stimulation | 
| tests of executive functions | Neuropsychological assessment : attentional functioning (TAP), executive functioning (BADS, working memory, go/no-go, stroop), memory (california verbal learning test) Improvement of executive functioning by tDCS will be assessed. | an average of two weeks | 
| Beck depression inventory scale |  | within 5 days after stimulation | 
| Clinical global impression scale |  | an average of two weeks | 
| Eye movements during facial emotion recognition task and attentional task | Recorded by Eye tracker.Measurement of total time spent on specific Region of interest (eyes, nose, mouth, emotional face) | within 5 days after stimulation | 
| Skin conductance measured in speed per microseconds | Recorded with physiologic data system (BIOPAC) | within 5 days after stimulation | 
| Heart rate measured in number of heart pulses per milliseconds | Recorded with physiologic data system (BIOPAC) | within 5 days after stimulation | 
| Respiratory frequency measured in number of respiratory cycles per minute | Recorded with physiologic data system(BIOPAC) | within 5 days after stimulation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tDCS, depression, neuromodulation, cognition