A Pilot Study of the Immediate Effects of DLPFC tDCS on Attention Bias in Depression

Study Overview
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Brief Summary
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Depression and other psychiatric conditions are marked by exaggerated, preferential processing (or attention bias) of negative information relative to neutral or positive information. This depression-related attention bias can be measured using the Dot Probe task and Visual Search, that allow assessment of the degree to which one shows bias toward negative information in the presence of neutral or positive information. A clinically effective treatment for depression is noninvasive brain stimulation with transcranial direct current stimulation (tDCS), targeting the dorsolateral prefrontal cortex (DLPFC), delivered in repeated sessions across a period of time. The study will test the effect of a single session of DLPFC tDCS on attention bias in patients with mild to moderate depression.

Detailed Description
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This prospective pilot study will recruit 25 female participants, ages 18-45 (inclusive), with mild to moderate depression (based on BDI-II score range 14-19 for mild and 20-28 for moderate) to determine if a single-session of tDCS can alter negative attention bias. The primary objective is to study if single-session tDCS will affect attention bias in depression and is not meant to treat depression. Subjects may or may not be receiving treatment for mild-moderate depression.

Official Title
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A Pilot Study of the Immediate Effects of DLPFC tDCS on Attention Bias in Depression

Conditions
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Depression

Intervention / Treatment
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* Device: Transcranial direct current stimulation (tDCS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18-45 Female Mild to moderate depression (determined by BDI-II scores of 14-19 and 20-28, respectively) If taking antidepressants, medication must be stable ≥ 30 days prior to screening Exclusion Criteria: Wide-Range Achievement Test-Fourth Edition (WRAT-4) Reading Subtest standard score <85 (to ensure understanding of test procedures) Insufficient visual and motor ability to operate the intervention and assessments as judged by treating neurologist or study staff Primary psychiatric disorder other than depression (based on MINI) Primary neurologic condition that would prevent ability to participate (as determined by study clinician). History of head trauma in the last year Medical device implants in the head or neck History or current uncontrolled seizure disorder Current substance abuse disorder . Pregnant or lactating women Skin disorder/sensitive skin near stimulation locations

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Female participants with Depression<br>Female participants with mild to moderate depression to determine if a single-session of tDCS can alter negative attention bias. The primary objective is to study if single-session tDCS will affect attention bias in depression and is not meant to treat depression. | Device: Transcranial direct current stimulation (tDCS)<br>* Participants will complete a single 30 minutes tDCS session targeting the left DLPFC while sitting in a comfortable position. At the end of the tDCS session possible side effects experienced during the tDCS session will be recorded along with their intensity (rated using the visual analogue scale, 0-10) and duration. The session can be aborted at any time for any reason if the participant wishes.The MINDD STIM tDCS system is composed of a management component, treatment module, single-use sponge patches and supporting patches, a headband to hold in position the sponge patches, and 2 cables. A trained study technician will program the stimulation device through the management component setting to the following stimulation parameters:Stimulation intensity: 2.0 mA or 1.5 mA; Stimulation duration: 30 minutes;Ramp up duration: 30 seconds (beginning of stimulation);Ramp down duration: 30 seconds (end of stimulation)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Level of Depression before Transcranial direct current stimulation (tDCS) | Measured by the Beck Depression Inventory (BDI-II) which is a brief, criteria-referenced assessment for measuring depression severity. The BDI-II consists of 21 items to assess the intensity of depression. Each item is a list of four statements arranged in increasing severity about a particular symptom of depression. | Study tDCS Administration Visit (Day1) | 
| Level of Anxiety before Transcranial direct current stimulation (tDCS) | Measured by the Beck Anxiety Inventory (BAI) which is a brief, criteria-referenced assessment for measuring anxiety severity and level. Participants respond to 21 items rated on a scale from 0 to 3. Each item is descriptive of subjective, somatic, or panic-related symptoms of anxiety. BAI has been found to discriminate well between anxious and non-anxious diagnostic groups in a variety of clinical populations. | Study tDCS Administration Visit (Day1) | 
| Intensity level of Depressive Symptoms | Measured by the Hamilton Depression Rating Scale (HAM-D) which is a 17-item measure that was designed to assess frequency and intensity of depressive symptoms in patients with Major Depressive Disorder (MDD). This measure contains somatic and suicidal ideation items and has demonstrated reliability, validity, and efficiency in adult populations | Study tDCS Administration Visit (Day1) | 
| Intensity level of Depressive Symptoms using SMDDS | The Symptoms of Major Depressive Disorder Scale (SMDDS) is a brief self reported measure for adults with MDD and measures specific symptom dimensions. The qualitative measure has good psychometric properties including high reliability and validity. | Study tDCS Administration Visit (Day1) | 
| Change in the negative affect after Transcranial direct current stimulation (tDCS) | The Positive and Negative Affect Schedule (PANAS-SF) will be administered before and after the Transcranial direct current stimulation (tDCS) session. This is a self-report questionnaire that consists of two 10-item scales (20 items total) to measure both positive and negative affect. | Pre-tDCS Administration Time (1 hour) and Post-tDCS Administration Time (1 hour) | 
| Change in the negative mood after Transcranial direct current stimulation (tDCS) | Will be assessed by using the Analog Mood Scale (AMS). This is a brief measure of positive and negative mood consisting of three questions (i.e., How anxious are you?, How sad are you?, and How happy are you?). Participants were told to indicate their present mood by identifying a location on a horizontal line divided into 30 equally distanced segments labeled 1 (not at all) to 30 (very much). | Pre-tDCS Administration Time (1 hour) and Post-tDCS Administration Time (1 hour) | 
| Change in attention bias using the Dot Probe task | The dot-probe task will be used to assess depression-related attention bias before and after tDCS administration.To complete the Dot-Probe task, participants will be shown two emotional images (e.g., sad and neutral pair or happy and neutral pair) simultaneously followed by a target in the location of one of the emotional images. Response latencies to targets replacing either the negative/positive or neutral images will be measured before and after training which will be the primary study outcome. | Pre-tDCS Administration Time (1 hour) and Post-tDCS Administration Time (1 hour) | 
| Change in attention bias using the Visual Search task | The Visual Search task will be administered to further assess attention bias, particularly examining the interference and facilitation effects in attention using emotional stimuli. The task uses emotional faces or words as stimuli, where the participant is instructed to search for the face that does not fit into the search set with respect to gender, where the target and distractors are expressing different or same emotions. This study will use this task as an outcome measure of Attention Bias alongside the Dot Probe task. For this task, mean response time (the time between display onset and button press) to the target stimulus for each stimulus type is measured as the main outcome variable. | Pre-tDCS Administration Time (1 hour) and Post-tDCS Administration Time (1 hour) |