VNS to treat Mood Disorders

A powerful, yet gentle and nuanced new option for treating anxiety, bipolar, depression, post-traumatic stress disorder, and related mood disorders has emerged.  Vagal nerve stimulation (VNS) is a form of bioelectric neuromodulation.  At Ormond Neuroscience we treat emotionally distressed people with VNS and are getting wonderful results. Importantly, the fact that it is not a drug means that there are none of the horrible side effects that so frequently accompany antidepressant medication and anxiolytic drugs.

The basic principles underpinning VNS are well-established.  VNS has been around for some decades but in the past always required invasive neurosurgery.  Fortunately, neuroanatomists have boundless curiosity and have been researching the vagal nerve.  New methods of implementing VNS followed from fortuitous discoveries regarding the anatomy of the vagal nerve.  It turns out that there is a branch of the vagal nerve in the ear.

Instead, we can pop an electrode onto your ear and in that way stimulate the vagal nerve.  So, VNS no longer requires invasive surgery, with all its risks and expenses. It’s that simple!

A woman undergoing VNS for depression. She looks blissful.

The Mind-Body Nerve

The vagal nerve is the 10th cranial nerve.  It is one of 12 different nerves that that connect a part of your body to your brain.  Specifically, the vagal nerve connects your brain to your major internal organs, including the heart, lungs, stomach, intestines, liver, pancreas, kidneys, spleen, oesophagus, larynx, and pharynx.  Precisely because of this connectivity, the vagal nerve is in a very real sense the mind-body nerve.  It facilitates the relationship between embodiment and the mental universe and that turns out to be critical to the treatment of depression and related emotional problems.

The peripheral nervous system comprises the autonomic and somatic nervous systems. The mind-body nerve plays a fundamental role in modulating the autonomic nervous system.  The autonomic nervous system regulates involuntary physiological processes such as heart rate, blood pressure, respiration, sexual arousal, and digestion. Notice, again, that all of these physiological processes all have a strong link to one’s emotional state.

Sympathetic vs Parasympathetic

Two complementary branches, the sympathetic nervous system and the parasympathetic nervous system, make up the autonomic nervous system.  While strictly independent systems, under normal circumstances the sympathetic and parasympathetic nervous systems are in a close seesaw relationship.  When one is active, the other is quiescent. Age, gender and health influence the degree of coupling.

The sympathetic nervous system is behind the “fight-flight response.”  It is the system that galvanises you into action when you feel fear, terror, anger, fright, anxiety, and related feelings.  Again, the link between emotional space and physiological processes is readily apparent.

Not to be left out, we have also bestowed a little catchphrase onto the parasympathetic nervous system, which is now described by the cachet “rest and digest.”  This is the component of the nervous system that is dominant when one feels safe, satiated, calm, relaxed, and at peace.  These are our nice warm fuzzy feelings.

Tweaking the Mind via the Body using VNS

In conditions such as chronic anxiety and major depressive disorder, there is frequently chronic hyper-activation of the sympathetic nervous system.  Panic attacks are an obvious example of the sympathetic nervous system spinning out of control.  Heart rate increases, blood pressure goes up, you start to sweat, you get cramping in your gut, and you cannot think clearly because of the overwhelming feelings of anxiety.  It is your sympathetic nervous system that is driving those panicked emotions.

To calm you down, we use VNS to stimulate the parasympathetic nervous system.  Increasing the activity of the parasympathetic nervous system results in deactivation of the fight-flight system. VNS usually brings about substantial physiological changes, reducing heart rate and lowering blood pressure. Reduced anxiety, easing of depression and more stable mood follow from the physiological changes induced by VNS. So, VNS modulates emotion through the body, containing the physiological states associated with chronic stress, depression, and anxiety.  The result is that you feel calmer and more emotionally stable. 

The Gut-Brain Axis

There is more to VNS than simply achieving a balance in the autonomic nervous system between the sympathetic and parasympathetic branches.  Another component of the mechanism of action of VNS is that it targets the gastrointestinal tract, resulting in improvements in the gut-brain axis. 

There has been an explosion of interest in the gut-brain axis, the connection between your mind and your gut.  We now know that depressed people have reduced diversity of intestinal microbiota, which has significant consequences for health.

Image alluding to the gut-brain axis

Let me explain.  Microbiota refers to the trillions of tiny bacteria that live in your gut.  In the modern world we place an emphasis on things being clean and sterile. Brainwashing makes us believe that all bacteria are bad. That’s not true.  If you did not have the microbiota in your gut, you would die of malnutrition.  The microbiota in your small intestine enable your body to absorb nutrients from the food that you eat.

It is this gut-brain relationship that gives meaning to the aphorism that “you are what you eat.”  Emotionally, when you are feeling bitter and twisted, acid about something that has happened, there is literally an increase in the pH of your gastrointestinal tract.  You literally become more acid!  Thus, your emotional state directly reflects your gastrointestinal physiology.  Conversely, improving gastrointestinal physiology by means of VNS, has benefits for your emotional well-being.

Inflammation

There is a growing awareness that psychological stress and unhappiness cause changes in your immune system (which fights disease) and in your endocrine system (hormones).  In turn, those changes are responsible for alterations in the functioning of your nervous system that result in mood disorders.  One consequence of that interaction is the association betwee depression and inflammation. Indeed, we now use antihistamines to treat depression.

When stressed and depressed, you produce a lot of cortisol, a stress hormone. Prolonged, elevated production of cortisol causes inflammation.  Amazingly, it turns out that vagal nerve stimulation reduces inflammation in a major way.  We believe that this is via activation of the cholinergic anti-inflammatory pathway (CAP)

This is yet another component of this marvellous treatment that induces changes in physiology to bring about benefits for emotional well-being.  VNS is so powerful precisely because it relies on stimulating the mind-body nerve, the 10th cranial nerve, the amazing vagal nerve.

Official Ratification of VNS

You may find reassurance in the fact that VNS has been ratified by the Food and Drug Administration (FDA) in the US.  It is officially certified as a recognised and approved treatment of depression. If you want more information, you’ll find a general overview of VNS elsewhere on our website.

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