Figure 1: Our psyche, nervous system and immune system are closely linked. Psychoneuroimmunology deals with these complex connections and interactions.
Thoughts, feelings and physical wellbeing are more closely connected than was long assumed. For example, stress can influence our immune system, while conversely the physical state can affect how we feel and think. It is precisely these complex interactions that are the focus of psychoneuroimmunology. In this blog post you will gain an insight into the field of research, learn central questions and find out what the findings of psychoneuroimmunology can mean for your health. In addition, we give you seven practical tips on how to use these connections in your everyday life.
What is psychoneuroimmunology?
Figure 2: Psychoneuroimmunology assumes that the best chances of healing exist when physical and mental health are viewed not in isolation but as closely interconnected.
Psychoneuroimmunology (abbreviated: PNI) is an interdisciplinary field of research that examines the complex links between psyche, nervous system and immune system. The focus is on the question of how exactly psychological processes—such as stress, social pressure or suppressed emotions—affect biological functions and vice versa. The field of research emerged as early as the 1970s based on the insight that the immune system does not operate independently of the brain, but is closely connected to the central nervous system and can also be influenced by psychological factors.
In contrast to conventional medicine, which typically views the body separately from the psyche, psychoneuroimmunology follows a holistic approach. The body is understood as a networked system in which psychological and physical processes are inextricably linked. However, Professor Christian Schubert, one of the most renowned figures in the field of psychoneuroimmunology, considers it important—particularly with regard to increasing chances of recovery—not to think of body and psyche separately.1 “The psyche and the social are precisely the instruments we need to become healthy,” says Schubert.
Conventional medicine works with a machine model of the human being that only considers material and visible aspects such as blood values, while the immaterial and invisible factors of human life are neglected. Instead, the physician calls for “new, more life-near research approaches” and a “more humane medicine” that takes into account the interfaces between brain and immune system.
How are brain, nervous system and immune system connected?
The brain, nervous system and immune system do not function independently of one another but are in close, reciprocal exchange. They communicate continuously to regulate bodily functions and respond appropriately to internal and external strains.
This exchange takes place via various pathways: on the one hand via neural connections—especially the vagus nerve—and on the other hand via hormonal signals such as stress hormones and immunological messengers known as cytokines. Immune cells possess receptors for classic neurotransmitters such as acetylcholine, noradrenaline, dopamine or serotonin. Conversely, cytokines can bind to receptors on nerve cells. In this way the nervous system influences the immune response, while immunological processes in turn modulate the activity of the nervous system.
In practice, this means that psychological strain and stress as well as states of relaxation can have direct effects on the immune system—and vice versa. Psychoneuroimmunology addresses these links and assumes that health does not arise in isolation within single systems but emerges from the dynamic interplay of psyche, nervous system and immune processes.
Inflammation and “low-grade inflammation” as a key mechanism
Figure 3: Silent inflammations are associated with various civilisation diseases such as type 2 diabetes, cardiovascular diseases and obesity.
Silent inflammation, or “low-grade inflammation”, refers to chronic, subclinical inflammatory processes in the body. As the name suggests, these often proceed without pronounced or clearly perceptible symptoms and therefore often remain unnoticed. Nevertheless, they have considerable significance for overall health and wellbeing.
Numerous studies show that chronic low-grade inflammation plays a central role in the development of many civilisation diseases such as cardiovascular disease, type 2 diabetes and obesity. Recent reviews demonstrate that such inflammatory processes are closely associated with the development and progression of chronic diseases, including cardiovascular conditions, metabolic disorders and certain types of cancer.2 Mental disorders such as depression and anxiety disorders are increasingly being linked in current research to chronic inflammatory processes. Studies show that affected individuals often exhibit elevated levels of proinflammatory markers such as interleukin-6 (IL-6) or C-reactive protein (CRP).3
There is also a close, bidirectional relationship between sleep and inflammation. Sleep deprivation or poor sleep quality can amplify inflammatory processes in the body. Conversely, inflammatory processes can affect sleep. This can easily create a vicious circle: poor sleep promotes inflammation, while raised inflammatory markers in turn impair sleep.4
But what role does psychoneuroimmunology play in this context? The vagus nerve is of central importance here. As an important component of the parasympathetic nervous system, it provides a direct link between the nervous system and the immune system and acts as a central communication axis between brain and body. The vagus nerve is also involved in the so-called cholinergic anti-inflammatory pathway. Through this mechanism the brain can actively regulate inflammatory processes in the body: when the vagus nerve is activated, it inhibits the release of proinflammatory cytokines and thus helps to attenuate inflammation. At the same time, the vagus nerve conveys information from the body—such as about inflammatory processes—back to the brain. This allows the organism to respond quickly to immunological changes and maintain equilibrium in the body (homeostasis).
Psychological strain: the perspective of psychoneuroimmunology
Figure 4: Distressing emotions, stress and loneliness can demonstrably influence the immune system and promote inflammatory processes.
Fear, sustained pressure and chronic stress not only impair psychological wellbeing but can also affect the immune system. From the perspective of psychoneuroimmunology these connections are readily explainable: psychological strain activates the body's stress system, especially the hypothalamic–pituitary–adrenal axis (HPA axis), leading to increased release of stress hormones such as cortisol. In the short term this can activate the immune system. In the long term, however, chronic stress often leads to dysregulation of the immune response, which is associated, among other things, with increased inflammatory propensity and a poorer defence against pathogens.
In addition to stress and distressing emotions such as anxiety, sadness or inner tension, loneliness can also promote immunological changes. Social isolation is increasingly regarded as an independent health risk factor and is associated with increased inflammatory activity as well as weakened immune function. Humans are social beings—when stable social relationships are lacking, this can measurably affect the immune system. Studies show that loneliness is linked to increased inflammatory activity and a reduced antiviral immune response.5
A core question of psychoneuroimmunology is how exactly psychological factors influence physical complaints and manifest, for example, as pain or fatigue. Conversely, numerous studies show that interventions such as psychotherapy, stress management or mindfulness training have positive effects on immune function and can strengthen the body's defences.6 Psycho- and immuno-hygiene are thus inextricably linked: those who actively maintain mental stability also support their immune system.
The influence of the gut–brain axis and the gut microbiome
The gut–brain axis and the trillions of microorganisms in our gut—the so-called gut microbiome—are particularly interesting bodily areas with which psychoneuroimmunology is also concerned. Many people are not aware that our gut microbiome not only affects digestion but also the immune system. This is not surprising when one realises that a large part of our immune system is located in the gut. Gut bacteria can influence immune cells and, among other things, regulate the release of signalling molecules (cytokines).
Moreover, gut bacteria produce numerous other substances such as short-chain fatty acids, which have anti-inflammatory effects, as well as neurotransmitters and hormones that can influence stress responses and emotions. Last but not least, there is also a direct neuronal connection between gut and brain: the so-called gut–brain axis. Signals from the gut are transmitted to the brain via the vagus nerve and vice versa. If the microbiome falls out of balance, this can disrupt both the immune system and communication with the brain. Possible consequences include enhanced inflammatory processes, a weakened gut barrier (“leaky gut”) and changes in stress processing and emotional regulation.
Using psychoneuroimmunology findings in everyday life: 7 tips
Figure 5: Those who understand the key links between psyche and immune system can use this knowledge deliberately in everyday life.
Psychoneuroimmunology vividly shows how closely mental and physical health are linked. You can make use of this knowledge: even small, targeted lifestyle changes can help reduce stress, support the immune system and sustainably improve overall wellbeing. With the following seven tips you can easily and effectively integrate key principles of psychoneuroimmunology into your daily life.
- Practice active stress management: Chronic stress can not only negatively affect the immune system but also promote inflammatory processes. Therefore, schedule conscious breaks throughout the day. Even a few minutes can have a positive effect. It is also worthwhile to incorporate proven relaxation techniques such as breathing exercises, meditation or yoga into your daily routine.
- Ensure restorative and sufficient sleep: Sleep is essential for the regulation of the immune system and inflammatory processes. A sleep routine with regular bedtimes and wake times as well as sufficient sleep duration (usually 7 to 9 hours) is crucial to support the regeneration of body and psyche.
- Cultivate social contacts: Being socially integrated has a demonstrably positive effect on the immune system, while loneliness can weaken defences. Therefore, consciously nurture your relationships and regularly make time for family, friendships and social activities.
- Incorporate movement into your daily life: Physical activity is one of the most important levers to support both psyche and immune system. Regular exercise has anti-inflammatory effects, supports the immune defences and improves stress resilience. Even moderate forms of exercise such as walks, gentle yoga or cycling can have very positive effects.
- Support your gut microbiome deliberately: Our gut microbiome is closely linked to the immune system and the psyche. To support beneficial gut bacteria and thus the gut–brain axis, a balanced, fibre-rich and plant-based diet is recommended. Fermented foods (probiotics) such as kefir, sauerkraut or kimchi can also positively influence the microbiome.
- Reflect consciously on your thoughts and emotions: Negative thought spirals and persistent emotional strain can manifest physically. Proven techniques such as mindfulness, journaling or cognitive restructuring can help improve how you cope with stress and distressing emotions.
- Plan regular rest and self-care: A phase of recovery should always follow physical or psychological tension. After stress the body needs sufficient time to return to the parasympathetic state (“rest & digest”) and to break down stress hormones. Therefore, regularly schedule activities that do you good and help your nervous system to calm down—be it an outing in nature, a creative hobby, reading or a deliberate digital detox.
Disclaimer
This article does not replace treatment by a qualified therapist. The basis of this contribution is studies and current literature. It must not be used for self-diagnosis or self-treatment. If in doubt, discuss any inspirations from this article with a therapist you trust.
Biographical
Katharina Korbach regularly writes blog posts about medicinal plants and natural active substances for Narayana Verlag. She became interested in language early on and began writing her own literary texts. A serious illness during her final school exams prompted an intensive engagement with health and nutrition issues that continues to this day. After repeated failures of conventional medical treatments, she opted for a more self-empowering, naturopathic therapeutic approach. A plant-based diet was a key factor in her path to recovery.
Katharina studied Cultural Studies (B.A.) and Applied Literary Studies (M.A.). In 2022 she published her debut novel “Sperling” with Berlin Verlag. She now lives in Berlin as a freelance author, medical editor and lecturer. In her free time she prefers to spend time with friends or at barre training. She also loves to travel and to try out new vegan recipes.
- Antenne Bayern: Get happy! Live more consciously – be more content. #32 Psychoneuroimmunology – with Prof. Dr. Dr. Christian Schubert. https://www.antenne.de/mediathek/serien/get-happy/0001j1t4tz1tyr1ktd29jr8n0h-32-psychoneuroimmunologie-mit-prof-dr-dr-christian-schubert (accessed: 29.03.2026).
- Cifuentes M, Verdejo HE, Castro PF, Corvalan AH, Ferreccio C, Quest AFG, Kogan MJ, Lavandero S. Low-Grade Chronic Inflammation: a Shared Mechanism for Chronic Diseases. Physiology (Bethesda). 2025 Jan 1. https://pubmed.ncbi.nlm.nih.gov/39078396/.
- Paganin W, Signorini S. Inflammatory biomarkers in depression: scoping review. BJPsych Open. 2024 Sep 30. https://pmc.ncbi.nlm.nih.gov/articles/PMC11536280/.
- Veler H. Sleep and Inflammation: Bidirectional Relationship. Sleep Med Clin. 2023 Jun. https://pubmed.ncbi.nlm.nih.gov/37120163/.
- Cole SW, Hawkley LC, Arevalo JM, Sung CY, Rose RM, Cacioppo JT. Social regulation of gene expression in human leukocytes. Genome Biol. 2007. https://pubmed.ncbi.nlm.nih.gov/17854483/.
- Black DS, Slavich GM. Mindfulness meditation and the immune system: a systematic review of randomized controlled trials. Ann N Y Acad Sci. 2016 Jun. https://pubmed.ncbi.nlm.nih.gov/26799456/.
Figure credits: Figure 1: VectorMine/shutterstock.com ; Figure 2: Nanci Santos Iglesias/shutterstock.com ; Figure 3: Magic mine/shutterstock.com ; Figure 4: Tero Vesalainen/shutterstock.com ; Figure 5: monshtein/shutterstock.com
08.04.2026
