Enhancement of Therapeutic Learning in OCD Using tDCS
Enhancement of Therapeutic Learning in Obsessive-compulsive Disorder Using Transcranial Direct Current Stimulation
Study Overview
Detailed Description
Most effective behavioral treatments of disordered anxiety involve repeated exposure to feared stimuli, which often results in systematic reductions in fearful responding to said stimuli. It is believed that this process results from successful fear extinction, a well-characterized learning process that is mediated by fear extinction brain circuitry. Namely, fear extinction is an inhibitory learning process that requires activation and plasticity within a variety of brain regions, including the medial prefrontal cortex (mPFC), which can exert inhibitory control over fearful responding and parts of the brain that drive said responding. Behavioral treatments of disordered anxiety, while effective, have serious limitations; many patients fail to respond at all or only partially respond to exposure-based treatments. One candidate reason for this is deficits in fear extinction learning or memory processes. The proposed study aims to examine the effects of non-invasive neuromodulation - namely, multifocal transcranial direct current stimulation (tDCS) targeting the mPFC - on therapeutic learning and memory among adults diagnosed with obsessive-compulsive disorder (OCD).
This study will recruit 26 subjects with OCD to complete a two-day experimental protocol to examine the effects of tDCS on therapeutic learning and memory, which will be measured with an exposure and response prevention laboratory challenge. On Day 1, OCD subjects will be randomized (1:1, double-blind) to receive Active (n = 13) or Sham (n = 13) tDCS prior to completing five 10-minute in vivo exposure exercises to assess the effects of tDCS on the acquisition of therapeutic learning. Subjects and raters (including those directing exposure sessions) will be blind to allocation. On Day 2, OCD subjects will return to complete five additional exposure trials to examine the effects of tDCS on recall of therapeutic learning. Subjective ratings of emotional distress (0-100) will be collected at baseline, before and after tDCS, and during each minute of each exposure trial. It is hypothesized that tDCS will improve the acquisition and recall of therapeutic learning (Aim 4); that participants randomized to Active tDCS would show more rapid reductions in subjective distress and would recall therapeutic learning on Day 2 when compared to participants randomized that Sham tDCS.
tDCS will be delivered using an 8-channel Starstim transcranial electric stimulator from Neuroelectrics. To target the mPFC, the anodal electrode will be placed over the frontal pole (Fpz, 10-20 EEG landmarks) and will be surrounded by five return (cathodal) electrodes in a circumferential array (AF7, AF8, F3, Fz, and F4). Subjects in the Active tDCS condition will receive 20 minutes of direct current stimulation for 20 minutes; current will be ramped in and out for 30 seconds at the beginning and end of the 20-minute period. Subjects in the Sham tDCS condition will receive the same electrode placement and ramping procedures, but no current will be delivered between ramping.
Linear mixed modeling will be used to assess within and between-trial exposure-relevant learning. Power analyses suggest that a sample of 24 (12 per condition) would adequately power a priori analyses when using linear mixed modeling. Mixed ANOVA will be used to assess recall of exposure-relevant learning. The proposed study will provide important preliminary data to examine the potential for medial prefrontal tDCS to augment exposure-relevant therapeutic learning.
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Contacts and Locations
Study Locations
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Connecticut
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New Haven, Connecticut, United States, 06511
- Connecticut Mental Health Center
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Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Ability to provide informed consent (as established by clinical interview), and voluntary, signed informed consent prior to the performance of any study-specific procedures;
- Ability and willingness to perform study-relevant clinical assessments and tDCS;
- Age 18-55;
- Medication free or stable (> 4 weeks) medication(s).
- A Diagnostic and Statistical Manual diagnosis of OCD; and
- Clinically significant obsessions and compulsions of at least moderate severity, as established by a score of at least 16 on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) during initial screening.
Exclusion Criteria:
- Any unstable medical, psychiatric, or neurological condition (including active or otherwise problematic suicidality) that may necessitate urgent treatment;
- Any substance dependence or severe substance abuse within the past 6 months;
- Daily use of psychotropic medications that substantially lower seizure threshold (e.g., clozapine);
- Daily use of psychotropic drugs that may interfere with extinction learning (e.g., anxiolytics);
- Any history of a psychotic disorder or of mania;
- Current active suicidal ideation or any suicidal intent;
- Any major neurological disease or history of major head trauma, including concussion with extended loss of consciousness, or of psychosurgery;
- Any history of epilepsy;
- Pregnancy;
- Any metal in the body or other contraindication to MRI scanning or tDCS;
- Any history of adverse effects to brain stimulation;
- Recent (< 8 weeks) change in psychotherapy - i.e. no recently instituted cognitive behavioral therapy will be permitted, but ongoing therapy of long duration will not constitute an exclusion;
- OCD symptoms that cannot be provoked with in vivo exposures in a laboratory environment
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Basic Science
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Double
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
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Active Comparator: Active tDCS
Current will be ramped in/out for 30 seconds at the begging and end of a 20-minute period and a constant current will be delivered for the 20-minutes between ramping.
|
Subjects will receive 20 minutes of multifocal transcranial direct current stimulation.
The anode will be placed over the frontal pole (Fpz, 10-20 EEG) and will be surrounded by 5 return electrodes (cathodes).
Current will be set at 1.5mA and will be ramped in/out at the begging and end of the 20-minutes of stimulation over the course of 30 seconds.
Other Names:
|
|
Sham Comparator: Sham tDCS
Current will be ramped in/out for 30 seconds at the begging and end of a 20-minute period during which no stimulation will be delivered.
|
Subjects will receive 20 minutes of multifocal transcranial direct current stimulation.
The anode will be placed over the frontal pole (Fpz, 10-20 EEG) and will be surrounded by 5 return electrodes (cathodes).
Current will be set at 1.5mA and will be ramped in/out at the begging and end of the 20-minutes of stimulation over the course of 30 seconds.
Other Names:
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What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Subjective Units of Distress
Time Frame: Collected every minute up through 50 minutes
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0-100 subjective distress self-report rating
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Collected every minute up through 50 minutes
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Collaborators and Investigators
Sponsor
Collaborators
Investigators
- Principal Investigator: Thomas Adams, PhD, Yale School of Medicine
Publications and helpful links
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- 1412015006_a
- 1K23MH111977 (U.S. NIH Grant/Contract)
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
IPD Plan Description
IPD Sharing Time Frame
IPD Sharing Supporting Information Type
- SAP
- ANALYTIC_CODE
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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