Modulation of Fear Extinction Processes Using Transcranial Electrical Stimulation

The aim of this study is to examine the effects of transcranial electrical stimulation on processes associated with fear extinction in healthy humans.

Study Overview

• Status: Completed
• Conditions: Anxiety; Stress Related Disorder
• Intervention / Treatment: Device: Sham stimulation (1.5 milliampere,30 seconds); Device: DC stimulation (1.5 milliampere, 20 minutes); Device: AC stimulation (1.5 milliampere,1.5 Hertz frequency)

Detailed Description

Research links the processes of fear conditioning and extinction to the treatment of anxiety and stress-related disorders. Moreover, considerable translational research examines the neural correlates of these processes. However, virtually no research in humans manipulates neural correlates of these processes, which limits basic-clinical integration. The present study aimed to use transcranial electrical stimulation (tES) to modulate processes associated with fear extinction in order to assess the potential utility of tES in enhancing exposure-based treatment. To this end, healthy participants underwent a three-day fear conditioning and extinction paradigm. Participants were randomly assigned into 3 groups, differing in terms of tES applied during the extinction learning phase (Day 2) and targeting the medial prefrontal cortex: 1) direct current (DC) stimulation, aimed at enhancing extinction learning; 2) alternate current (AC) stimulation, aimed at interfering with reconsolidation of the fear memory activated during the extinction phase; and 3) sham stimulation. The outcome measures (outlined next) involve the assessment of extinction recall during a test phase (Day 3). Successful modulation of extinction learning by tES would be reflected in enhanced extinction recall.

• Study Type: Interventional
• Enrollment (Actual): 45
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

Exclusion Criteria:

• Self-reported major psychiatric condition
• Screening specific for electrical stimulation (psychotropic medication, metal implants in head, epilepsy or seizure history)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Sham; Sham electrical stimulation	Device: Sham stimulation (1.5 milliampere,30 seconds); Other Names: DC Stimulator Plus (neuroConn, Germany), serial 0118
Experimental: DC: Direct current; Direct current electrical stimulation	Device: DC stimulation (1.5 milliampere, 20 minutes); Other Names: DC Stimulator Plus (neuroConn, Germany), serial 0118
Experimental: AC: Alternating current; Alternating current electrical stimulation	Device: AC stimulation (1.5 milliampere,1.5 Hertz frequency); Other Names: DC Stimulator Plus (neuroConn, Germany), serial 0118

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Galvanic Skin Response (GSR)	GSR was measured throughout the task using 2 standard electrodes on the fingers. Measurement units were in micro-Siemens; scores were square-root-transformed (a common method in GSR studies). A higher level of GSR in response to stimuli is taken to reflect greater physiological fear response, and thus worse in the context of the relevance of the study conditions to the treatment of anxiety disorders. Scores were collected in response to presentation of the CS+ (the stimulus conditioned to be associated with an aversive outcome) and the CS- (the stimulus not conditioned to be associated with any outcome).	During three-day experimental task

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Self-reported Fear Rankings	Participants marked how fearful they are of stimuli used in the task on a single 10-point scale (1=not afraid, 10=extremely afraid). Higher scores therefore reflect greater fear and are worse in the context of treatment for anxiety disorders. Scores were collected in response to presentation of the CS+ (the stimulus conditioned to be associated with an aversive outcome) and the CS- (the stimulus not conditioned to be associated with any outcome).	During three-day experimental task

Collaborators and Investigators

• Sponsor: Tel Aviv University

Publications and helpful links

General Publications

• Abend R, Jalon I, Gurevitch G, Sar-El R, Shechner T, Pine DS, Hendler T, Bar-Haim Y. Modulation of fear extinction processes using transcranial electrical stimulation. Transl Psychiatry. 2016 Oct 11;6(10):e913. doi: 10.1038/tp.2016.197.

Study record dates

Study Major Dates

• Study Start: September 1, 2014
• Primary Completion (Actual): April 1, 2015
• Study Completion (Actual): April 1, 2015

Study Registration Dates

• First Submitted: March 24, 2016
• First Submitted That Met QC Criteria: March 24, 2016
• First Posted (Estimate): March 30, 2016

Study Record Updates

• Last Update Posted (Actual): June 14, 2017
• Last Update Submitted That Met QC Criteria: May 13, 2017
• Last Verified: May 1, 2017

More Information

Terms related to this study

• Other Study ID Numbers: TASMC-13-TH-334

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO