tVNS and Approach-Avoidance Behavior in Anhedonia and Anxiety
This study investigates if anhedonia and anxiety symptoms are associated with alterations in reinforcement learning, effort trade-offs for wins vs. punishments, and foraging behavior under threat. Moreover, it will investigate whether these processes can be influenced by a metabolic load and/or transcutaneous vagus ner
| Condition(s) | Healthy Participants, Anxiety Disorders (With High Anxiety Symptoms), Depressive Disorders (With High Anhedonia Symptoms), Comorbid Depression and Anxiety Disorder (With High Anhedonia and High Anxiet |
|---|---|
| Status | Recruiting |
| Phase | NA |
| Study type | Interventional |
| Summary | This study investigates if anhedonia and anxiety symptoms are associated with alterations in reinforcement learning, effort trade-offs for wins vs. punishments, and foraging behavior under threat. Moreover, it will investigate whether these processes can be influenced by a metabolic load and/or transcutaneous vagus nerve stimulation (tVNS). The project consists of (a) an online reinforcement learning study, used to characterize learning, reward sensitivity, and meta-cognition, and (b) a laboratory study in which participants first undergo fMRI while completing an effort-based decision-making task. Second, participants will complete two sessions in VR with randomized active or sham tVNS during a foraging task before and after a caloric load with concurrent physiological recordings. |
| Who can participate | 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 (met |
| Ages | 18 Years to 40 Years |
| Sex | All |
| Accepts healthy volunteers | Yes |
| Lead sponsor | Dr. Nils B. Kroemer |
| Locations | Bonn, Germany |
| Start date | 2026-03-23 |
| NCT ID | NCT07476469 |
| Official listing | https://clinicaltrials.gov/study/NCT07476469 |