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Slow-Paced Breathing and Electrical Vagus Nerve Stimulation as Add-on Treatments for Depression
Sponsor: Elisabeth Balint
Summary
Depression is a common mental health condition, and standard psychiatric therapies do not always lead to satisfactory recovery. As a result, there is an urgent need for effective, complementary treatments. The vagus nerve is the main component of the parasympathetic nervous system, which regulates bodily rest and calms inflammatory responses. In clinical depression, vagus nerve activity is often reduced, and low-grade inflammation is frequently observed. While electrical stimulation of the vagus nerve via surgically implanted devices has been shown to reduce depressive symptoms, its invasive nature carries risks. Non-invasive alternatives-such as slow-paced breathing exercises or gentle transcutaneous electrical stimulation at the outer ear-offer promising ways to stimulate this nerve safely without surgery. The main purpose of this clinical study is to evaluate whether slow-paced breathing is an effective add-on therapy to reduce depressive symptoms in hospitalized patients compared to standard multimodal psychiatric treatment. Additionally, the study investigates whether the effects of slow-paced breathing are comparable to transcutaneous auricular vagus nerve stimulation (tVNS) and whether they differ from a sham (placebo) stimulation. A total of 160 adult inpatients with at least a moderate depressive episode will be randomly assigned to one of four groups during their hospital stay: Group 1 (Slow-Paced Breathing): Participants practice a guided, slow-paced breathing technique (inhaling for 4 seconds, exhaling for 6 seconds) for 20 minutes, 3 times daily, 5 days per week over 4 weeks. Group 2 (Electrical Vagus Nerve Stimulation): Participants receive non-invasive electrical stimulation to the outer ear canal using a certified medical device (tVNS) for 20 minutes, 3 times daily, 5 days per week over 4 weeks. Group 3 (Sham Stimulation): Participants receive identical-looking electrical stimulation applied to the earlobe (an area lacking vagal nerve fibers) on the same schedule, serving as an active control. Participants do not know whether they receive active or sham stimulation. Group 4 (Treatment as Usual): Participants receive the standard multimodal inpatient psychiatric treatment program alone, alongside daily logging of relaxation and mindfulness activities. All participants continue to receive standard psychiatric care. Depressive symptoms are assessed using the Beck Depression Inventory-II (BDI-II) and the Hamilton Depression Rating Scale. In addition, heart rate variability (HRV) via a 24-hour recording and blood inflammatory markers (such as IL-6 and CRP) are measured before and after the 4-week intervention period to explore the physiological mechanisms of vagus activation. A follow-up questionnaire is completed after 3 months to assess long-term outcomes.
Official title: Add-on Therapy of Depression Using Vagus Nerve Stimulation
Key Details
Gender
All
Age Range
18 Years - 60 Years
Study Type
INTERVENTIONAL
Enrollment
160
Start Date
2026-11
Completion Date
2030-09
Last Updated
2026-10-02
Healthy Volunteers
No
Conditions
Interventions
Slow-Paced Breathing
Guided slow-paced breathing technique with prolonged exhalation (4 seconds inhalation, 6 seconds exhalation, resulting in 6 breaths per minute) to stimulate the vagus nerve. Conducted for 20 minutes, 3 times daily, 5 days per week over a period of 4 weeks in a seated position, accompanied by daily protocol logging. Administered in addition to standard inpatient psychiatric care.
Transcutaneous Auricular Vagus Nerve Stimulation (tVNS)
Electrical nerve stimulation using a CE-certified class IIa medical device (tVNS® by tVNS Technologies GmbH). Stimulation is applied via custom ear electrodes to the cymba conchae of the left outer ear canal to transcutaneously activate vagal afferents. Parameters: 25 Hz frequency, 250 µs pulse duration, 28 s ON / 32 s OFF cycle, intensity adjusted individually between 0.1 and 5.0 mA below pain threshold. Administered for 20 minutes, 3 times daily, 5 days per week over 4 weeks as an add-on to standard inpatient care.
Sham Auricular Electrical Stimulation
Sham sensory control using identical stimulation parameters (25 Hz, 250 µs pulses, 28 s ON / 32 s OFF) and device setup as active tVNS, but the stimulation electrode is attached to the left earlobe, a region devoid of vagal innervation. Conducted for 20 minutes, 3 times daily, 5 days per week for 4 weeks in addition to standard inpatient care.
Treatment as Usual (TAU)
Standard multimodal inpatient psychiatric and psychotherapeutic treatment program including medication, psychotherapy, and clinical ward routine, accompanied by daily logging of relaxation exercises.
Locations (1)
Privatklinik Meiringen
Meiringen, Switzerland