Recruiting

Observational Study

Sponsor:

Emory University

Code:

NCT01627301

Conditions

Post-traumatic Stress Disorder

Prehypertension

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Accepted

Interventions

Device-Guided Breathing (DGB)

Sham DGB

Transcutaneous Vagal Nerve Stimulation (tVNS)

Sham tVNS

Study Details

Brief summary:

Post-traumatic stress disorder (PTSD) is a highly prevalent anxiety disorder that is associated with an increased risk of cardiovascular (CV) disease and hypertension. One potential mechanism is overactivation of the sympathetic nervous system (SNS), both at rest and particularly during stress. This study will evaluate whether 8 weeks of daily DGB therapy or transcutaneous vagus nerve stimulation (tVNS) therapy improves SNS activity at rest and during stress.

Conditions

Post-traumatic Stress Disorder

Prehypertension

Study ID

NCT01627301

Start date

Jul, 2012

Status verified date

Jan, 2026

Completion date

Dec, 2027

Anticipated

Primary completion date

Dec, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Accepted

Inclusion Criteria:

  • prehypertensive and normotensive veterans with PTSD, and prehypertensive and normotensive veterans without PTSD (controls)

Exclusion Criteria:

  • heart or vascular disease
  • illicit drug use within the last 6 months
  • excessive alcohol use (>2 drinks per day)
  • pregnancy
  • autonomic dysfunction
  • medications known to affect SNS (clonidine)
  • treatment with monoamine oxidase (MAO) inhibitors within the last 14 days
  • any serious systemic disease

Study Design

Enrollment

120 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Device-guided Breathing (DGB)

Participants randomized to the DGB group use a device to guide their breathing to a slow breathing rate.

sham comparator: Sham DGB

Participants randomized to the sham DGB group use a device identical to the DGB device but respiratory rates are not guided lower than the physiological rate.

experimental: Transcutaneous Vagal Nerve Stimulation (tVNS)

Participants randomized to use a tVNS device to deliver mild electrical stimulation to the vagal nerve.

sham comparator: Sham tVNS

Participants randomized to use the sham tVNS device which vibrates but does not stimulate the vagal nerve.

Interventions

Device-Guided Breathing (DGB)

The RESPeRATE device will be used for 15 minutes of device-guided breathing daily for 8 weeks. The participant places the elastic belt with a respiration sensor around the upper abdomen, and wears earbuds for audio feedback. The device monitors the breathing rate, calculates inspiration and expiration times, and generates a personalized melody of two distinct ascending and descending tones for inhalation versus exhalation. Users effortlessly entrain their breathing pattern with the tones, and the device gradually guides the user to a prolonged expiration time and slower respiratory rate (to < 10 breaths/minute). The device automatically stores usage data, allowing for quantification of adherence and performance.

Sham DGB

The sham device is identical to the DGB device, except it does not guide respiratory rates to slow down and instead maintains a rate of 14 breaths per minute. The sham device is used for 15 minutes per day for 8 weeks.

Transcutaneous Vagal Nerve Stimulation (tVNS)

tVNS is a noninvasive method that involves placing a device over the skin overlying the vagus nerve on the neck. The device delivers mild electrical stimulation, using transcutaneous electrical nerve stimulation (TENS) unit. The stimulation is increased until there is a vibration and slight muscle contraction in the lower face or neck. Then the stimulation is delivered for 2 minutes on the left side of the neck, and on the right side of the neck, for a total of 4 minutes. The tVNS device is used twice daily for 8 weeks.

Sham tVNS

Sham stimulation is delivered using a device that is identical to the gammaCore device but is programed to deliver a lower frequency that can be felt by the participant but does not actually stimulate the vagus nerve. The sham device is used twice daily for 8 weeks.

Primary outcome measure

  • Change in Muscle Sympathetic Nerve Activity (MSNA) Burst Frequency at Rest [ Time Frame: Baseline, Week 8 ]
  • Change in Baroreflex Sensitivity (BRS) at Rest [ Time Frame: Baseline, Week 8 ]
  • Change in MSNA Burst Frequency While Under Mental Stress [ Time Frame: Baseline, Week 8 ]
  • Change in BRS While Under Mental Stress [ Time Frame: Baseline, Week 8 ]

Central Contacts and Locations

Central contacts

Deirdre Dixon, MS

404-321-6111deirdre.dixon@emory.edu

Jeanie Park, MD

404-321-6111

Locations

Atlanta VA Medical Center

Recruiting

Decatur, Georgia, United States, 30033

More Information

Sponsor

Emory University

Last update posted

Jan 15, 2026

Last verified

Jan, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Emory University on 2026-01-15.