Efficacy of Intensified Transcranial Direct Current Stimulation in Obsessive-compulsive Disorder

Study Overview
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Brief Summary
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This is a randomized, double-blind, parallel-group, sham-controlled trial that aims to investigate the effectiveness of transcranial direct current stimulation (TDCS) on improving symptoms, quality of life, depression, and cognitive functions in 39 patients with obsessive-compulsive disorder (OCD) that are randomized in 3 experimental groups.

Official Title
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Efficacy of Transcranial Direct Current Stimulation (tDCS) in Symptoms, Quality of Life, Cognitive Deficits and Brain Physiology of Patients With Obsessive-compulsive Disorder

Conditions
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Obsessive-Compulsive Symptom

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: Diagnosis of Obsessive-compulsive Disorder by a psychiatrist and DSM-5-based behavioral checklist being 18-50 years old providing written informed consent If female, negative urine pregnancy test stable medication regime especially the classical neuroleptics and all CNS-activating medications, if taken, 4-6 weeks before the experiment and during the experiment Exclusion Criteria: smoker pregnancy alcohol or substance dependence history of seizure history of neurological disorder history of head injury presence of ferromagnetic objects in the body that are contraindicated for brain stimulation of the head (pacemakers or other implanted electrical devices, brain stimulators, some types of dental implants, aneurysm clips, metallic prostheses, permanent eyeliner, implanted delivery pump, or shrapnel fragments) or fear of enclosed spaces.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: tDCS group 1<br>In the first experimental group, the TDCS intervention protocol consists of 10 sessions of 20 minutes of 1 mA electrical stimulation on 5 consecutive days with two sessions per day. | Device: transcranial direct current stimulation<br>* Patients will receive 10 sessions of 20 minutes of either 1 mA, 2 mA or sham electrical stimulation on 5 consecutive days<br>* Other names: tDCS;|
| Experimental: tDCS group 2<br>In the second experimental group, the TDCS intervention protocol consists of 10 sessions of 20 minutes of 2 mA electrical stimulation on 5 consecutive days with two sessions per day. | Device: transcranial direct current stimulation<br>* Patients will receive 10 sessions of 20 minutes of either 1 mA, 2 mA or sham electrical stimulation on 5 consecutive days<br>* Other names: tDCS;|
| Placebo Comparator: Control group<br>In the placebo group, the TDCS intervention protocol consists of 10 sessions of 20 minutes of sham electrical stimulation on 5 consecutive days with two sessions per day. | Device: transcranial direct current stimulation<br>* Patients will receive 10 sessions of 20 minutes of either 1 mA, 2 mA or sham electrical stimulation on 5 consecutive days<br>* Other names: tDCS;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Yale-Brown Obsessive-Compulsive (Y-BOCS) rating scale | Score in the Yale-Brown Obsessive-Compulsive (Y-BOCS). Total scores on the measure range from 0 to 40, with a score of 0-7 indicating subclinical symptoms, 8-15 mild symptoms, 16-23 moderate symptoms, 24-31 severe symptoms and 32-40 extreme symptoms. | up to 1 month after the intervention | 
| Beck Anxiety Questionnaire (BAI) | Score in the Beck Anxiety Questionnaire (BAI). The BAI scores are classified as minimal anxiety (0 to 7), mild anxiety (8 to 15), moderate anxiety (16 to 25), and severe anxiety (30 to 63). | up to 1 month after the intervention | 
| Response inhibition task 1 | Performance in the response inhibition tasks (Flanker test) | up to 1 month after the intervention | 
| Working memory task | Performance in the working memory task as an executive function task | up to 1 month after the intervention | 
| Response inhibition task 2 | Performance in the response inhibition tasks (Go/No-Go task) | up to 1 month after the intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Beck Depression Questionnaire (BDI-II) | Score in the Beck Depression Questionnaire (BDI-II). The BDI-II scores are classified as below: Score of 1-10: These ups and downs are considered normal. Score of 11-16: Mild mood disturbance. Score of 17-20: Borderline clinical depression. Score of 21-30: Moderate depression. Score of 31-40: Severe depression. Score of 40+ Extreme depression. | up to 1 month after the intervention | 
| Quality of Life Questionnaire (WHOQUL) | Score in the Quality of Life Questionnaire. It has 26 items and each item is rated on a 5-point scale with a higher score indicative of higher quality of life. | up to 1 month after the intervention | 
| electroencephalogram (EEG) oscillatory power | Change in the EEG power in alpha, delta, theta and beta bands | up to 1 month after the intervention | 
| electroencephalogram (EEG) functional connectivity | Change in the EEG functional connectivity | up to 1 month after the intervention |