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Completed

NCT Number: NCT02723188

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.

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Key information

Conditions

Stress Related Disorder Anxiety Anxiety Disorders Mental Disorders

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Exclusion criteria

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

Treatment and study plan

Sham stimulation (1.5 milliampere,30 seconds)

Device

Other names: DC Stimulator Plus (neuroConn, Germany), serial 0118

DC stimulation (1.5 milliampere, 20 minutes)

Device

Other names: DC Stimulator Plus (neuroConn, Germany), serial 0118

AC stimulation (1.5 milliampere,1.5 Hertz frequency)

Device

Other names: DC Stimulator Plus (neuroConn, Germany), serial 0118

Primary outcomes

  1. Galvanic Skin Response (GSR)

    Time frame: During three-day experimental task

    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).

Secondary outcomes

  1. Self-reported Fear Rankings

    Time frame: During three-day experimental task

    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).

Sponsors and collaborators

Lead sponsor

Tel Aviv University

Other

Registry information

Important dates

Study start
2014
Primary completion
2015
Study completion
2015
First posted
Mar 30, 2016
Registry last updated
Jun 14, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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