The Role of the Vagus Nerve in Anxiety and Mood Disorders Explained

The vagus nerve is one of the most important nerves in your body. It is the tenth cranial nerve and part of your autonomic nervous system, which controls things your body does automatically—like breathing, heartbeat, and digestion.

This nerve runs from your brainstem (in a part called the medulla oblongata) all the way down to your chest and abdomen. The vagus nerve’s efferent fibers originate in the dorsal motor nucleus of the medulla oblongata, which is crucial for autonomic regulation. It connects to the gastrointestinal tract, heart, lungs, and even your immune system, and has a key relationship with the enteric nervous system. The enteric nervous system, sometimes called the ‘second brain,’ contains millions of nerve cells that communicate with the vagus nerve to regulate gut function. Because it does so much, the vagus nerve plays a big role in how we feel—both physically and emotionally.

How the Vagus Nerve Affects the Nervous System

The vagus nerve helps balance two parts of the nervous system:

• The sympathetic nervous system, which creates the stress response (also known as “fight or flight”)
• The parasympathetic nervous systems, which work together to help the body rest and relax (called “rest and digest”)

The parasympathetic nervous systems are crucial branches of the autonomic nervous system, primarily mediated by the vagus nerve, and regulate functions like slowing your heart rate, improving digestion, and calming the mind. When the vagus nerve function is strong, it helps your body relax and recover from chronic stress.

Stress responses involve a complex interplay between the sympathetic and parasympathetic nervous systems, with the vagus nerve playing a key role in restoring balance after stress. When vagus nerve activity is low, your body may stay stuck in stress mode, which can make problems like anxiety symptoms, chronic inflammation, and digestive issues worse.

Vagal Tone and Emotional Regulation

Doctors often talk about something called vagal tone. This means how well the vagus nerve is working. A high vagal tone is good—it means your body can quickly return to a calm state after stress. A low vagal tone, on the other hand, is linked to depressive symptoms, anxiety disorders, and even gastrointestinal disorders like irritable bowel syndrome and inflammatory bowel disease.

Improving your vagal tone helps control your blood pressure, calm your gut-brain axis (the connection between your gut and brain), and improve your mental health. People with better vagus nerve stimulation often feel more balanced and less overwhelmed. Improved vagal tone may also help support the health and function of brain cells involved in memory, decision-making, and emotional regulation.

The Connection Between the Vagus Nerve and Anxiety

When the vagus nerve isn’t working well—called impaired vagal function—it can lead to or worsen psychiatric disorders like major depressive disorder, posttraumatic stress disorder, and treatment-resistant anxiety disorders. This is because the vagus nerve helps carry electrical impulses and signals between your body and brain.

The vagus nerve also works with your immune system to control inflammatory responses. It modulates the immune response by influencing immune cells such as macrophages and T cells. If the vagus nerve doesn’t calm inflammation properly, proinflammatory cytokines like tumor necrosis factor alpha can increase. The vagus nerve can also promote the release of anti inflammatory cytokines, which help reduce inflammation and maintain immune homeostasis. This kind of systemic inflammation has been linked to comorbid depression and anxiety.

Through the cholinergic anti-inflammatory pathway, vagus nerve stimulation can activate the splenic sympathetic nerve, which helps regulate cytokine production and immune activity. Studies have shown that even patients suffering from chronic colitis, abdominal pain, and mental health issues may benefit when we stimulate the vagus nerve—either through deep breathing, lifestyle changes, or devices that provide transcutaneous vagus nerve stimulation or direct electrical stimulation.

Mood Disorders and Impaired Vagus Nerve Function

When the vagus nerve doesn’t work properly, it can affect both your body and brain. People with low vagal tone often experience stronger anxiety symptoms and more intense depressive symptoms. This is because the vagus nerve helps balance the signals in your nervous system and keeps your brain function stable.

Research has shown that impaired vagal function is linked to many psychiatric and inflammatory disorders, such as:

• Major depressive disorder
• Posttraumatic stress disorder (a type of anxiety disorder)
• Treatment-resistant depression
• Treatment-resistant anxiety disorders

Studies on depressed patients have demonstrated changes in gut barrier function, immune markers, and microbiota composition, highlighting the biological links between depression and gut health.

These conditions can be harder to manage if the body’s ability to calm down is weak. This happens when the parasympathetic nervous system isn’t strong enough to lower the stress created by the sympathetic nerves.

Research on Vagus Nerve Stimulation for Mental Health

Because the vagus nerve plays such an important role in mental health, scientists have developed special ways to improve its function. One method is called vagus nerve stimulation (VNS). This treatment uses intermittent electrical impulses to activate the vagus nerve and improve how it works.

Vagal nerve stimulation has been used for people with treatment-resistant depression and anxiety disorders. It can help send better electrical signals to the prefrontal cortex (the part of the brain that controls thoughts and emotions) and to other areas connected to mood.

Some newer tools even allow for transcutaneous vagus nerve stimulation, which means the stimulation happens through the skin—often by placing a small device near the ear or neck. These methods aim to lower inflammatory responses, balance gut hormones, and support better communication between the gut brain and the rest of the nervous system. Vagus nerve stimulation may also help regulate the gut immune system, reducing excessive inflammation in the gastrointestinal tract. Research has explored the effects of vagus nerve stimulation in conditions like ulcerative colitis, showing potential benefits for reducing gut inflammation and improving symptoms.

Natural Ways to Support Your Vagus Nerve

While medical treatments like VNS are helpful, there are also natural ways to stimulate your vagus nerve daily that anyone can try. These support both your mental health and physical well-being.

Here are a few simple methods:

• Deep breathing: Breathing slowly and deeply helps activate the parasympathetic nervous system and improve vagal nerve tone.
• Cold exposure: Splashing cold water on your face or taking a cold shower can activate the left vagus nerve and calm your stress response.
• Humming or singing: These activities stimulate the vagal afferent neurons in your throat and promote relaxation.
• Light exercise: Physical activity boosts blood flow, supports the digestive system, and helps regulate the gut microbiota.
• Meditation and mindfulness: These can calm the cholinergic anti-inflammatory pathway, helping to reduce chronic inflammation and improve vagus nerve function.

Even a foot massage or taking time to laugh with friends can help! These actions send calming signals to the brain and lower the increased risk of psychiatric disorders linked to chronic stress.

8. Conclusion: Caring for Your Vagus Nerve to Support Mental Wellness

The vagus nerve is more than just a nerve—it’s a powerful tool for balancing your mind and body. When it’s working well, it helps control stress, lower blood pressure, support digestion, and reduce anxiety symptoms.

If you’re dealing with anxiety, depression, or gastrointestinal issues, improving your vagal tone through both medical and natural approaches may help.

By taking small steps—like deep breathing, managing stress, and staying connected to others—you can gently stimulate the vagus nerve and support better emotional health, one day at a time.