Does Transcutaneous Vagal Nerve Stimulation Improves Fear Extinction in Humans

NCT ID: NCT02113306

Last Updated: 2014-04-14

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 50 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2014-07-31

Brief Summary

A recent study with rats showed that electrical stimulation of the vagus nerve (VNS) facilitates extinction of fear (Pena, Engineer, & McIntyre, Biological Psychiatry, 2013). The hypothesized mechanism is that VNS both enhances memory consolidation (by increasing noradrenergic neurotransmission) and reduces anxiety (thus: preventing fear responses to the CS which may re-consolidate the fear memory). The effect was only apparent when VNS occurred during exposure of the fear conditioned stimulus (CS), and not when stimulation was given immediately following exposure. These results may have implications for the treatment of anxiety disorders in humans. However, until recently, the only means to investigate the effects of VNS on human fear learning would have required the invasive implantation of vagus nerve stimulators. This has fortunately changed, as a non-invasive transcutaneous VNS device has been approved for use in the E.U. for the treatment of psychological disorders.

This study proposes to use a t-VNS to investigate its effects on fear learning and extinction in (healthy) humans. Previous research has only investigated the effects it has on human mood and memory. The results obtained suggest that it reduces negative affect and enhances memory, findings which are consistent with those reported for rats. It is thus reasonable to expect that t-VNS will facilitate the extinction of fear in humans.

The present study aims to answer the following research questions:

Does t-VNS during extinction training:

1. accelerates extinction curves

2. reduces spontaneous recovery of previously extinguished fear

3. reduce re-acquisition of fear

4. reduce generalization of fear to other stimuli that resemble the CS+?

5. facilitates the generalization of inhibitory learning to stimuli that resemble the CS-?

Conditions

Healthy Adults

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: SINGLE

Study Groups

t-VNS

electrical stimulation of the concha of the ear

30sec trains of 0.25msec-duration monophasic square wave pulses at 25Hz, with a stimulation intensity not exceeding 0.5 mA

Group Type: EXPERIMENTAL

t-VNS

Intervention Type: DEVICE

The device that will be used is approved for systematic use by those with epilepsy and depression in the European Union. It has been used in studies of acute stimulation with healthy participants with no significant changes in heart rate or breathing (Kraus et al., 2007; Busch et al., 2013).

sham t-VNS

Sham stimulation of the earlobe will be conducted by positioning the electrode upside down

30sec trains of 0.25msec-duration monophasic square wave pulses at 25Hz, with a stimulation intensity not exceeding 0.5 mA

Group Type: SHAM_COMPARATOR

sham stimulation

Intervention Type: DEVICE

electrodes will be put upside down

Interventions

t-VNS

The device that will be used is approved for systematic use by those with epilepsy and depression in the European Union. It has been used in studies of acute stimulation with healthy participants with no significant changes in heart rate or breathing (Kraus et al., 2007; Busch et al., 2013).

Intervention Type: DEVICE

sham stimulation

electrodes will be put upside down

Intervention Type: DEVICE

Other Intervention Names

NEMOS®, Cerbomed, Erlangen, Germany; NEMOS®, Cerbomed, Erlangen, Germany

Eligibility Criteria

Inclusion Criteria

• healthy men and women aged 16 - 50 years

Exclusion Criteria

• current or past psychiatric or neurological disorder
• use of psychopharmaca
• use of medication that affects autonomic nervous functioning (e.g., bèta-blockers)
• current cardiac or respiratory disorder
• pregnancy

• Minimum Eligible Age: 16 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

KU Leuven

OTHER

Sponsor Role: collaborator

Universitaire Ziekenhuizen KU Leuven

OTHER

Sponsor Role: lead

Responsible Party

Ilse Van Diest

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Ilse Van Diest, PhD

Role: PRINCIPAL_INVESTIGATOR

KU Leuven

Locations

Faculty of Psychology and Educational Science

Leuven, , Belgium

Countries

Belgium

Central Contacts

Ilse Van Diest, PhD

Role: CONTACT

ilse.vandiest@ppw.kuleuven.be

+32 16 32 60 29

Facility Contacts

Ilse Van Diest, PhD

Role: primary

Other Identifiers

t-VNS extinction

Identifier Type: -

Identifier Source: org_study_id