Vagus Nerve Stimulation and Mood Regulation

VNS and mood disorders

How Neuromodulation Can Support Emotional Stability and Autonomic Balance

Mood disorders such as depression, anxiety, bipolar disorder, and post-traumatic stress disorder are not purely “mental” conditions. They involve complex interactions between brain networks, autonomic regulation, stress physiology, and bodily state.

Vagus nerve stimulation (VNS) does not treat mood disorders by suppressing symptoms or replacing psychotherapy or medication. Instead, it modulates the physiological systems that shape emotional regulation, particularly when used as part of a broader, integrative clinical approach, such as our Neuroharmonics programme.

Mood Disorders as Disorders of Regulation

Emotional states emerge from the interaction between:

  • brain networks involved in prediction, attention, and salience
  • autonomic nervous system regulation
  • endocrine and immune signalling
  • bodily sensations and interoceptive feedback

In many people with chronic anxiety or depression, these systems become rigidly biased toward threat, hyperarousal, or withdrawal, reducing emotional flexibility and resilience.

From this perspective, mood disorders can be understood as disorders of regulatory balance and adaptability, rather than isolated disturbances of thought or mood alone. Importantly, the severity of symptoms does not always map directly onto underlying biological dysfunction. Individuals with similar diagnoses or symptom profiles can differ markedly in how stable, flexible, and responsive their regulatory systems are. This variability reflects the integrity of the systems that govern adaptation, rather than the presence of symptoms alone.

The Role of the Autonomic Nervous System

The autonomic nervous system regulates involuntary physiological processes such as heart rate, blood pressure, respiration, digestion, and immune activity. It consists of interacting sympathetic and parasympathetic components that operate dynamically, not as a simple seesaw.

  • Sympathetic activity supports mobilisation, vigilance, and threat response
  • Parasympathetic activity supports restoration, safety signalling, and recovery

Health depends on flexible regulation between these systems. In mood and anxiety disorders, this flexibility is often reduced, leading to:

  • persistent physiological arousal or shutdown
  • altered stress reactivity
  • reduced heart-rate variability
  • heightened bodily signals of threat or fatigue

Why the Vagus Nerve Matters for Emotional Regulation

The vagus nerve plays a central role in conveying information from the body to the brain, shaping how the brain interprets internal states related to safety, threat, and wellbeing.

Through its afferent (input) pathways, the vagus nerve influences:

  • brainstem nuclei involved in arousal and attention
  • limbic circuits related to emotion
  • cortical systems involved in regulation and meaning

As a result, the vagus nerve is a key pathway through which bodily state influences emotional experience. This also helps explain why interventions that target physiological regulation can influence emotional outcomes, even when they do not act directly on thoughts or mood content.

How VNS Influences Mood and Emotional Stability

Non-invasive auricular VNS can influence autonomic and brainstem regulatory circuits that shape emotional tone and stress physiology.

When applied conservatively and in context, VNS may:

  • support parasympathetic regulation
  • reduce excessive physiological arousal
  • improve autonomic flexibility
  • modulate stress-related brain–body signalling

Importantly, VNS does not impose calm or suppress emotion. Instead, it may help restore the physiological capacity for regulation, making emotional states more responsive to psychotherapy, behavioural change, and lived experience. In this way, the aim is not to eliminate emotional states, but to restore the flexibility with which they are regulated and integrated.

vagal nerve stimulation regulates physiology

Mood, Stress, and Inflammation

Psychological stress and mood disorders are associated with changes in immune and inflammatory signalling. These processes interact bidirectionally with the nervous system, influencing energy levels, motivation, cognition, and emotional tone.

The vagus nerve is involved in neural pathways that regulate inflammatory responses. While this research is still evolving, it provides a clear biological link between stress physiology, inflammation, and mood — and helps explain why interventions targeting regulation rather than symptoms alone are clinically relevant.

What the Evidence Shows — and What It Does Not

  • Implanted VNS is approved in some jurisdictions for treatment-resistant depression
  • Non-invasive VNS, including auricular approaches, is supported by a growing research literature exploring its effects on mood, anxiety, stress regulation, and autonomic function
  • Evidence strength varies, and response is individual

VNS should be understood as an adjunctive intervention, not a standalone treatment or cure for mood disorders.

Can vagus nerve stimulation replace antidepressant medication or psychotherapy?

Vagus nerve stimulation should not be understood as a simple replacement for psychotherapy, medication, or broader clinical care. Mood disorders are complex conditions involving brain function, physiology, lived experience, stress regulation, and context, and treatment often benefits from a combination of approaches.

For many people, psychotherapy and/or antidepressant medication may form part of an appropriate treatment plan. However, not everyone responds well to medication, and some individuals prefer to minimise or avoid antidepressant use because of side effects, limited benefit, or personal preference.

In this context, vagus nerve stimulation may represent an alternative or additional physiological approach aimed at supporting autonomic regulation, emotional flexibility, and stress-related brain–body function.

Implanted VNS is FDA-approved in the United States for treatment-resistant depression, reflecting evidence that neuromodulation can be clinically relevant in severe or persistent depression. However, the broader role of VNS should not necessarily be limited only to situations in which all other treatments have failed.

At Ormond Neuroscience, non-invasive auricular VNS is used as part of a broader regulatory approach tailored to the individual. Depending on the person and clinical context, this may include psychotherapy, behavioural intervention, medication, lifestyle modification, or combinations of these approaches. The goal is not simply symptom suppression, but improving the physiological conditions that support emotional regulation and recovery over time.

How We Use VNS in the Context of Mood Disorders

At Ormond Neuroscience, VNS is always used as part of a broader, integrative approach, which may include:

  • psychotherapy
  • behavioural and lifestyle intervention
  • attention to sleep, health, and context
  • medication where appropriate

VNS is applied conservatively, at sub-threshold intensities, and with careful attention to individual response. The goal is not symptom suppression, but supporting the physiological conditions that allow emotional regulation to improve.

Who May Benefit — and Who May Not

VNS may be considered for individuals whose emotional difficulties are strongly associated with:

  • chronic stress or hyperarousal
  • autonomic dysregulation
  • reduced physiological flexibility

It is not appropriate for everyone, and careful clinical assessment is essential.

Limits and Expectations

VNS does not:

  • replace psychotherapy or medication
  • bypass the need for psychological work
  • guarantee emotional improvement

Meaningful change in mood and emotional stability typically arises from the interaction between physiology, experience, and context, over time.

In Summary

Mood disorders reflect disturbances in how the brain and body regulate stress, emotion, and internal state. Vagus nerve stimulation offers a physiologically grounded way to support regulation, not by overriding emotion, but by modulating the systems that shape it.

In this context, improvement in mood is understood as a consequence of improved regulation, rather than as a direct effect of symptom suppression.

Learn More

If you’ve wondered about the terminology, “vagus” is a noun referring to the nerve itself, whereas “vagal” is an adjective referring to things related to the nerve, such as vagal pathways, vagal modulation, or the commonly used (but strictly incorrect) phrase “vagal nerve stimulation.”

For further information about vagus nerve stimulation and its clinical applications, please see the following pages:

Ormond Neuroscience Web Pages

Talks and Interviews

For those interested in a deeper exploration of the neuroscience and clinical application of VNS, the following talks and interviews provide additional context:

Get in Touch

If you would like to explore whether vagus nerve stimulation is appropriate for your situation, please get in touch to arrange an interview.

Selected References and Further Reading

Barrett, L. F., & Simmons, W. K. (2015). Interoceptive predictions in the brain. Nature Reviews Neuroscience, 16(7), 419–429.
Nature Reviews Neuroscience

Butt, M. F., Albusoda, A., Farmer, A. D., & Aziz, Q. (2020). The anatomical basis for transcutaneous auricular vagus nerve stimulation. Journal of Anatomy, 236(4), 588–611.
Journal of Anatomy

Craig, A. D. (2002). How do you feel? Interoception: The sense of the physiological condition of the body. Nature Reviews Neuroscience, 3(8), 655–666.
Nature Reviews Neuroscience

Ferstl, M., Kühnel, A., Klaus, J., Lin, W. M., & Kroemer, N. B. (2024). Non-invasive vagus nerve stimulation conditions increased invigoration and wanting in depression. Comprehensive Psychiatry, 130, 152488.
Comprehensive Psychiatry

Kleckner, I. R., Zhang, J., Touroutoglou, A., Chanes, L., Xia, C., Simmons, W. K., et al. (2017). Evidence for a large-scale brain system supporting allostasis and interoception in humans. Nature Human Behaviour, 1, 0069.
Nature Human Behaviour

Neuser, M. P., Teckentrup, V., Kühnel, A., Hallschmid, M., Walter, M., & Kroemer, N. B. (2020). Vagus nerve stimulation boosts the drive to work for rewards. Nature Communications, 11, 3555.
Nature Communications

Paciorek, A., & Skora, L. I. (2020). Vagus nerve stimulation as a gateway to interoception. Frontiers in Psychology, 11, 1659.
Frontiers in Psychology

Paulus, M. P., & Stein, M. B. (2010). Interoception in anxiety and depression. Brain Structure and Function, 214(5–6), 451–463.
Brain Structure and Function

Sterling, P. (2012). Allostasis: A model of predictive regulation. Physiology & Behavior, 106(1), 5–15.
Physiology & Behavior

Ventura-Bort, C., Wendt, J., Hamm, A. O., & Weymar, M. (2024). Transcutaneous auricular vagus nerve stimulation modulates the processing of interoceptive prediction error signals and their role in allostatic regulation. Psychophysiology, 61(3).
Psychophysiology

Yuan, H., & Silberstein, S. D. (2016). Vagus nerve and vagus nerve stimulation, a comprehensive review: Part III. Headache disorders, mood disorders and future directions. Headache, 56(3), 479–490.
Headache Journal

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