tVNS Effects on Motivation in Depression

Not Applicable

Completed

• Conditions: Major Depressive Disorder
• Interventions: Device: transcutaneous vagus nerve stimulation; Device: sham stimulation

• Registration Number: NCT05120336
• Lead Sponsor: University Hospital Tuebingen

Brief Summary

Attaining goals or rewards commonly entails response costs. In light of cost and benefits, how do participants decide what effort should be put in to give it a shot? Figuratively, you may "go with your gut", but the literal contribution of the gut-brain axis in allocating effort is poorly understood to date. Here, the investigators propose to investigate non-invasive transcutaneous vagal nerve stimulation (tVNS) as a potential modulator of energy metabolism and response vigor. Since the neural mechanisms causing the diverse cognitive and behavioral effects of the stimulation remain largely elusive, the investigators will use computational modeling of instrumental behavior and determine the primary metabolic effects of the stimulation. The investigators hypothesize that tVNS will lead to activation of afferent targets in the brain. In turn, the elicited brain activation is expected to mediate the cognitive effects of the stimulation. This may affect both sides of the utility equation because anti-depressive effects may correspond to boosting the benefit of effort whereas anti-nociceptive effects may reduce perceived costs of effort. Collectively, dissecting the cognitive effects of non-invasive tVNS in healthy individuals may facilitate the more widespread use as a treatment in mental disorders that are characterized by metabolic alterations such as depression.

Detailed Description

Not available

Study Timeline

• Study Start: 2019-12-11
• Primary Completion: 2021-01-29
• Study Completion: 2021-01-29
• Status Verified: 2021-10
• Study First Submitted: 2021-10-18
• Study First Submitted QC: 2021-11-02
• Study First Posted: 2021-11-15
• Last Update Submitted: 2021-11-24
• Last Update Posted: 2021-12-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 67

Inclusion Criteria

• 30 kg/m^2 > BMI > 18.5 kg/m^2

Exclusion Criteria

lifetime

• brain injury

• coronary heart disease and occurred apoplexy

• schizophrenia

• bipolar disorder

• implants (e.g., cochlea implant)

• asthma

  12 month

• severe substance use disorders (DSM-V), except tobacco

• obessive compulsive disorder

• somatic symptom disorder

• eating disorder

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Patients with major depressive disorders: sham first, active taVNS second	sham stimulation	participants with depression receive sham stimulation in the first session (biphasic stimulation with a frequenyc of 25 Hz, 30s OFF/30s ON at the earlobe (sham) for 1.5 h). In a second identical session, they receive active stimulation with the same parameters (at the cymba conchae).
Non-depressed control participants: active taVNS first, sham second	sham stimulation	Non-depressed control participants receive active stimulation in the first session (biphasic stimulation with a frequenyc of 25 Hz, 30s OFF/30s ON at the cymba conchae (active) for 1.5 h). In a second identical session, they receive sham stimulation with the same parameters (at the earlobe).
Patients with major depressive disorders: active taVNS first, sham second	sham stimulation	participants with depression receive active stimulation in the first session (biphasic stimulation with a frequenyc of 25 Hz, 30s OFF/30s ON at the cymba conchae (active) for 1.5 h). In a second identical session, they receive sham stimulation with the same parameters (at the earlobe).
Non-depressed control participants: sham first, active taVNS second	transcutaneous vagus nerve stimulation	Non-depressed control participants receive sham stimulation in the first session (biphasic stimulation with a frequenyc of 25 Hz, 30s OFF/30s ON at the earlobe (sham) for 1.5 h). In a second identical session, they receive active stimulation with the same parameters (at the cymba conchae).
Non-depressed control participants: sham first, active taVNS second	sham stimulation	Non-depressed control participants receive sham stimulation in the first session (biphasic stimulation with a frequenyc of 25 Hz, 30s OFF/30s ON at the earlobe (sham) for 1.5 h). In a second identical session, they receive active stimulation with the same parameters (at the cymba conchae).
Patients with major depressive disorders: sham first, active taVNS second	transcutaneous vagus nerve stimulation	participants with depression receive sham stimulation in the first session (biphasic stimulation with a frequenyc of 25 Hz, 30s OFF/30s ON at the earlobe (sham) for 1.5 h). In a second identical session, they receive active stimulation with the same parameters (at the cymba conchae).
Non-depressed control participants: active taVNS first, sham second	transcutaneous vagus nerve stimulation	Non-depressed control participants receive active stimulation in the first session (biphasic stimulation with a frequenyc of 25 Hz, 30s OFF/30s ON at the cymba conchae (active) for 1.5 h). In a second identical session, they receive sham stimulation with the same parameters (at the earlobe).
Patients with major depressive disorders: active taVNS first, sham second	transcutaneous vagus nerve stimulation	participants with depression receive active stimulation in the first session (biphasic stimulation with a frequenyc of 25 Hz, 30s OFF/30s ON at the cymba conchae (active) for 1.5 h). In a second identical session, they receive sham stimulation with the same parameters (at the earlobe).

Primary Outcome Measures

Name	Time	Method
Motivation to work for rewards: frequency of button presses to gain food an monetary rewards	during stimulation (compared to sham)	Operationalized via the relative frequency of button presses on an Xbox controller in an effort allocation task during either the first seconds of each trial (invigoration) or each complete trial (maintenance)
Food reward ratings	during stimulation (compared to sham)	Operationalized via visual analogue scale ratings of liking \[-100 - 100\] and wanting \[0-100\] in a food cue reactivity task
Reward learning: correct choices	during stimulation (compared to sham)	Operationalized via number of correct value-based choices in a valenced go/no-go learning task
Positive and negative mood	Pre stimulation and 20 minutes post stimulation (compared to sham)	Operationalized via visual analogue ratings (0-100) of positive and negative affect schedule mood items

Trial Locations

Locations (1)

Department of Psychiatry & Psychotherapy, University of Tübingen; 🇩🇪 Tübingen, BW, Germany