Transcutaneous auricular vagus nerve stimulation (taVNS) 

By, SANTHOSH KUMAR

Transcutaneous auricular vagus nerve stimulation is a non-invasive alternate treatment for those suffering from major depressive disorder(MDD). MDD is a life-threatening psychiatric illness that is characterized by symptoms like anhedonia, reduced energy, impaired cognition, and even suicidal tendency.

The most widely preferred treatment for MDD is antidepressant medications, deep brain stimulation and behavioral therapy, electroconvulsive therapy, psychotherapy, etc. However, the response rate achieved from these medications is much lower.

The important mechanism found in these MDD patients is their dysregulation of the immune system which is found to be responsible for depression relapse and failure of antidepressants. Certain stimuli like inflammation, stress, etc. activate the immune cells of blood and other peripheral sites. This leads to the activation of proinflammatory cytokine activation. 

Vagus nerve stimulation however found to have an anti-inflammatory effect on central serotonin levels and also affects the cortisol levels. taVNS shows anti-inflammatory properties putting the vagus nerve at the interface of neurotransmitters, neuroendocrine system, neuroinflammation, and immunity.

VNS involves implantation of the device through surgery as electrodes onto the cervical branch of the vagus nerve. The taVNS in turn deliver impulses to the auricular branch of the vagus nerve(ABVN) and easy target that passes the human ear. The side effects of taVNS are also minimal and skin irritation may be the most common side effect. 

Thus taVNS might be the solution for the uprising condition which is Major Depression Disorder (MDD).