Transcutaneous vagus nerve stimulation to shift approach–avoidance behavior in people with anxiety and anhedonia
Vagus Nerve Stimulation and Approach-Avoidance Behavior in Anhedonia and Anxiety
This project tests whether non-invasive ear vagus nerve stimulation (tVNS), before and after a small meal, can change decision-making and foraging under threat in adults with high anxiety and/or high anhedonia and in healthy volunteers.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 104 (estimated) |
| Ages | 18 Years to 40 Years |
| Sex | All |
| Sponsor | University of Bonn Academic / other |
| Locations | 1 site (Bonn) |
| Trial ID | NCT07476469 on ClinicalTrials.gov |
What this trial studies
The work combines an online reinforcement-learning task, MRI-based phenotyping, and in-lab virtual reality to probe how anxiety and anhedonia affect learning, effort trade-offs, and foraging under threat. After online screening and diagnostic visits, participants undergo fMRI while performing an effort-based decision task, then complete two randomized VR sessions with active or sham tVNS both when hungry and after a standardized ~400 kcal milkshake. Physiological signals such as heart rate are recorded while participants freely move in VR so behavioral adaptations and recovery can be measured. Groups include healthy controls and participants with high anxiety, high anhedonia, or both, matched for age, sex, and BMI.
Who should consider this trial
Good fit: Adults aged 18–40 with BMI 18.5–30 kg/m² who can provide consent, undergo MRI and VR procedures, and have either high anxiety symptoms, high anhedonia symptoms, both, or are healthy controls are the intended participants.
Not a fit: People with severe neurological disorders, bipolar disorder, schizophrenia, recent eating disorders, certain cardiovascular or metabolic conditions, pregnancy, MRI contraindications, or impaired movement, hearing, or uncorrected vision are not eligible and unlikely to benefit from participation.
Why it matters
Potential benefit: If successful, this could point to a non-drug way to rebalance approach and avoidance behaviors and potentially improve functioning in people with anxiety or anhedonia.
How similar studies have performed: Previous small studies have shown that tVNS can influence mood, learning, and autonomic function, but combining tVNS with VR foraging and a metabolic manipulation in anxiety/anhedonia is a relatively novel approach.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * BMI between 18,5 and 30,0 kg/m2, * between 18 and 40 years of age, and * be able and willing to provide informed consent. Exclusion Criteria: * have a high risk of suicide, * have a lifetime diagnosis of severe neurological disorder (incl. ADHD), schizophrenia, bipolar disorder, or severe substance abuse, posttraumatic stress disorder, obsessive-compulsive disorder, diabetes, epilepsy, or coronary heart disease * have fulfilled criteria for an eating disorder or somatic symptom disorder within the last 12-months, * take medication (except psychopharmacological medication for MDD or anxiety), patients have to be on stable psychopharmacological medication for at least two months before study participation (minimizing confounding effects) * contraindications for MRI (metal implants or claustrophobia) * for female individuals if they are pregnant or nursing at the time, * impaired movement ability or hearing * impaired, uncorrected vision (need contact lenses) * contraindications for tVNS hearing aids or diseased skin on the right ear.
Where this trial is running
Bonn
- University Hospital Bonn, Bonn, Germany — Bonn, Germany (Recruiting)
Study contacts
- Study coordinator: Dr. Anne Kühnel
- Email: akuehnel@uni-bonn.de
- Phone: +49 228 28711519
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.