Study of non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) intervention to improve the reward motivation and response inhibition of major depression disorder and its brain network mechanism.
Anhedonia is the core symptom of MDD, which means they have deficits in processing rewards.MDD get lesser positive feelings than healthy controls from rewards as they could not use the reward outcome to update the value of a stimulus, which in consequence impedes their reward motivation or response inhibition and worsen their symptom. This study is dedicated to revealing how reward motivation or response inhibition ability could be intervened by taVNS intervention, which has been proven is highly relevant to reward motivation and response inhibition ability. Implementing a safer intervention of taVNS stimulation might help us to prove a better treatment for patients. All patients underwent a medical evaluation that included physical examination and routine laboratory studies before and after taVNS stimulation treatment. Before and after the taVNS treatment, depression symptom of each participant was assessed by the Hamilton Depression Scale and the Beck Depression Self-Rating Scale. The anhedonia severity was evaluated by The Temporal Experience of Pleasure Scale, the Self-Report Apathy Evaluation Scale, the Positive Valence system scale and the Motivation and Pleasure Scale. The neuroimaging data are collected using event-related potentials during the effort reward task and stop signal task before and after the intervention. Patients were randomly allocated into an active group and a sham group. This study plans to enroll a minimum total sample size of 30 participants in active and sham group respectively according to the Power and Sample Size program. The decision to enroll a patient was always made prior to randomization. Each patient will be treated for 4 weeks with 25Hz taVNS. Each participant was interviewed in detail about the adverse event of the taVNS intervention during 10 days. Every participant should take part in the study voluntarily and sign an informed consent form before the study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
60
taVNS was developed as a non-invasive variant of VNS where the vagus nerve is stimulated through the skin of the auricle, which has become a promising avenue for research and, potentially, treatment of various disorders. Commonly, taVNS is applied via the ear targeting the auricular branch of the vagus nerve, where the stimulation elicits far-field potentials. In line with preclinical studies, acute taVNS enhances invigoration of effort and response inhibition capability.
Anhui Medical University
Hefei, Anhui, China
Change from baseline in Hamilton Depression Scale
The participants' depression symptom assessed by the Hamilton Depression Scale change from baseline after the treatment. Score reference value: \<7 points, no depression;7 to 17points, mild depression;18to 24 points, moderate depression; \> 24 points, severe depression. If remission rate reaches 50%, the treatment will be considered effective.
Time frame: baseline;10days after treatment; 1month and 3 month post-treatment
Change from baseline in Apathy Evaluation Scale
The participants' reward motivation assessed by the Apathy Evaluation Scale change from baseline after the treatment. Score reference value: \<37 points, no apathy; ≥37points, apathy. If remission rate reaches 25%, the treatment will be considered effective.
Time frame: baseline;10days after treatment; 1month and 3 month post-treatment
The change from baseline in behavioral results of effort reward task
Behavioral results changed and discount parameters generated from the model change from baseline after the treatment.
Time frame: baseline;4 weeks post-treatment
The change from baseline in event-related brain potentials during the effort reward task
The amplitudes of brain potentials of reward-related positivity and P3 assessed by event-related brain potentials methods change from baseline after the treatment.
Time frame: baseline;4 weeks post-treatment
The change from baseline in behavioral results of stop signal task
Behavioral results changed from baseline after the treatment.
Time frame: baseline;4 weeks post-treatment
The change from baseline in event-related brain potentials during the stop signal task
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Cue-evoked cue-P3 and N2 mean wave amplitude changes and latencies, as well as spectral intensities. Wave amplitude and latency of target-P3 and N2 evoked by target stimuli, and spectral activity.
Time frame: baseline;4 weeks post-treatment