A Distinguished University Scientist and Rudy Professor Emerita of Biology at Indiana University, Dr. Carter has spent more than five decades exploring the biology of attachment, bonding, and caregiving. Her pioneering work on prairie voles transformed our understanding of monogamy and social connection, helping reveal how oxytocin and vasopressin are deeply intertwined with early attachment, trauma, stress physiology, development, and the biological foundations of human connection. 

What emerges from Dr. Carter’s work is a far richer picture of oxytocin: not simply as a “feel-good” chemical, but as part of the biological systems that help human beings determine whether they are safe enough to bond, regulate, recover and repair. 

“Biology is not separate from context. It is shaped by it.” 

Oxytocin is not just about bonding 

For many years, oxytocin was viewed primarily as a female reproductive hormone involved in birth and lactation. As Dr. Carter explained, that understanding was far too narrow. 

Oxytocin is produced in the brain but also acts throughout the body, influencing stress physiology, autonomic regulation, immune function and social behaviour in both males and females. Dr. Carter also discussed emerging evidence suggesting interactions between oxytocin and the microbiome. 

This helps explain why oxytocin is increasingly relevant to mental health research. 

If depression, anxiety, insomnia and irritability are not only psychological experiences, but also involve dysregulation of stress systems and the nervous system, then the molecules involved in safety, attachment and physiological regulation deserve much more attention. 

Oxytocin appears to play an important role in this wider network. It is involved not only in reproduction and bonding, but also in how the body responds to social bonding, stress regulation, caregiving, and the body’s capacity for rest and restoration. 

Safety is context-dependent 

A central theme throughout my conversation with Dr. Carter was that oxytocin cannot be understood outside context. Whether oxytocin promotes calm, bonding and regulation depends heavily on whether the nervous system perceives safety. 

A hug from a trusted loved one is not the same as unwanted physical contact from a stranger. Even physical closeness or caregiving may not feel regulating if safety is absent. Oxytocin is not a magic hormone that can be separated from relationship, environment or perception. 

This has important implications for trauma-informed care. The body does not respond only to events themselves, but also to the meaning and safety it assigns to them. A person who has experienced early relational trauma may struggle to interpret closeness as safe, even when connection is what they most need. 

Attachment, in this sense, is not only emotional. It is physiological. 

Oxytocin and vasopressin: regulating survival and stress 

Dr. Carter explored the relationship between oxytocin and vasopressin, two closely related peptides involved in attachment, stress responses and survival. 

Vasopressin is evolutionarily older and is more strongly associated with arousal, vigilance and defensive survival responses. Oxytocin, by contrast, is more closely linked to bonding, caregiving, stress regulation and social attachment. 

Both systems are essential. Survival depends not only on responding to threat, but also on the ability to return to states of safety, connection and restoration after stress. 

This offers a more nuanced understanding of resilience. Mental wellbeing is not simply about suppressing distress or “staying strong”, but about whether the nervous system can move flexibly between protection and connection, mobilisation and recovery. 

Early attachment teaches the nervous system what safety feels like 

Our conversation explored how early caregiving environments help shape the developing stress response. Pregnancy, birth, touch, feeding, attachment and social support all contribute to how the infant nervous system learns regulation and safety. 

Dr. Carter discussed how early relational experiences may help calibrate biological systems involved in stress responses, attachment and emotional regulation later in life. This does not mean that early adversity determines a person’s future, but it does suggest that relationships and environment become biologically embedded in important ways. 

Mental health, therefore, does not begin only with conscious thought or adult experience. It develops through ongoing interactions between biology, caregiving, stress and environment from the earliest stages of life. 

Why this matters for integrative mental health 

For integrative mental health, this has profound implications. Mental health cannot be understood purely through thoughts, symptoms or neurotransmitters in isolation. Stress physiology, attachment, immune signalling, early experience, relationships and environment all help shape whether the nervous system remains stuck in protection or is able to move towards connection and repair. 

Dr. Carter’s work ultimately offers important insights for modern mental health care, highlighting not only the central role of oxytocin, but also how profoundly its effects are shaped by relationships, environment, perception, and a sense of safety. This more integrated understanding points to the importance of creating the physiological and relational conditions in which meaningful healing can begin. 

Listen to my conversation with Dr. Sue Carter on The MindHealth360 Show to explore how oxytocin, attachment and stress physiology may shape mental health across the lifespan. 

Thank you for reading.
Warmest wishes,  

Kirkland Newman, Founder, MindHealth360 

🌱 Your guide to root-cause mental health.  

• See Sue Carter speak at this year’s Integrative Medicine for Mental Health (IMMH) Conference – 4 days, 50+ speakers, up to 40 CE credits, exploring integrative medicine psychiatry and root-cause approaches to mental health 

• The MindHealth360 Show – Subscribe for evidence-based conversations with leading clinicians and researchers, delivered to your inbox 🎧  

• Join the community – Ongoing insights, events and conversations shaping the field. Plus, free content when you sign up to the newsletter. 

The post How oxytocin shapes stress, attachment, safety and resilience, and why it matters for integrative mental health appeared first on MindHealth360.

We now know this is due to three interacting systems: the amygdala, the wider limbic system, and the stress response – and in particular how these systems interface with immune signalling and inflammation.

The amygdala – the brain’s threat detector

The amygdala, the brain’s alarm centre, rapidly scans for danger and activates survival responses before conscious thought intervenes. In acute stress, this response is protective and adaptive.

Emerging research in psychoneuroimmunology however, suggests that inflammatory signalling due to physiological or psychological stressors, can increase amygdala reactivity and alter connectivity with regulatory regions of the prefrontal cortex. This signalling can be triggered by chronic infections, environmental toxins, traumatic brain injury, autoimmune processes, metabolic dysfunction, sleep disruption or sustained psychological stress.

Both physiological and psychological stressors activate overlapping neuroendocrine and inflammatory pathways. The body does not sharply distinguish between emotional trauma and biological threat; in both cases, stress hormones and immune mediators can become mobilised.

When this signalling becomes persistent, the alarm system becomes easier to trigger and harder to calm. In other words, the threat detector becomes sensitised and trigger-happy.

The limbic system – emotional memory and regulation

The amygdala forms part of the broader limbic system, which includes structures such as the hippocampus and interconnected salience networks. Together, these circuits shape emotional memory, stress appraisal and behavioural responses.

Under sustained stress – whether driven by psychological trauma, sleep disruption, chronic infections, toxic exposure, immune activation or metabolic strain – limbic circuitry may remain in a heightened state of vigilance.

This is where knowledge of the limbic loop becomes beneficial.

When the stress response reinforces itself

In a sensitised system, the sequence looks different:

1. The amygdala detects threat (external or internal)

2. The autonomic nervous system activates (fight, flight or freeze)

3. Immune and inflammatory mediators increase

4. Neural activity and cerebral perfusion shift

5. Sensitivity to internal sensations rises

6. The brain interprets this activation as a further threat

And the loop continues.

Research in post-viral and inflammatory conditions has observed that inflammatory cytokines can influence neural activity within mood and threat networks, while altered cerebral perfusion has been observed in post-viral and inflammatory conditions. These patterns help explain why some individuals feel persistently ‘switched on’. The nervous system is not choosing to stay activated, it is responding to ongoing signals of danger.

At a deeper biological level, this persistent activation may also reflect what Dr. Robert Naviaux has termed the, ‘Cell Danger Response’ – a protective metabolic state in which cells prioritise defence over growth and repair. In acute stress, this response is adaptive. When prolonged, however, sustained cellular danger signalling may reinforce immune activation and stress circuitry. A nervous system that feels ‘stuck’ may therefore reflect both circuit-level sensitisation and cellular-level defence responses remaining in the ‘on’ position, and the body loses the ability to return to a calm, restorative baseline, which can sustain or worsen chronic symptoms.

The immune and gut amplifiers

The stress response is of course not purely neurological. The gut–immune axis plays a central role. Growing evidence around the gut–brain axis indicates the gastrointestinal tract houses a large proportion of the body’s immune tissue, and disruption of the microbiome or intestinal barrier can contribute to chronic immune signalling.

Inflammatory mediators can influence limbic circuitry, while vagal signalling links gut state to brain state. When immune activation persists, the stress response may be easier to trigger.

This does not mean every case of anxiety is inflammatory in origin. It does mean that biological stressors may amplify psychological ones – and vice versa. Psychological stress can itself induce inflammatory signalling. Whether the trigger is emotional or physiological, the body mounts a coordinated stress response that includes immune activation; it does not meaningfully differentiate between the two.

Why ‘stuck’ does not mean broken

Addressing this requires nuance. Foundational physiological stability – including sleep, oxygenation, metabolic and nutritional balance and immune regulation – supports nervous system resilience. Equally, trauma-informed psychological support and autonomic regulation strategies remain essential as part of lifestyle and therapeutic interventions designed to bring the nervous and immune systems back into balance.

The limbic loop framework does not eliminate psychological explanations. Instead, it integrates them with immune, neuroendocrine and vascular biology. The key insight is therefore that mental health symptoms often characterised as ‘psychological’ usually emerge from complex interactions between stress circuitry, inflammation and physiology. When these systems reinforce one another, the nervous system may remain in threat mode longer than intended, and mental health symptoms appear or persist.

Understanding this interaction allows clinicians and patients alike to move beyond the false divide between ‘mental’ and ‘physical’ illness. The amygdala, the immune system, the neuroendocrine system and the stress response – whether driven by psychological or physiological stressors – are not separate domains. They are parts of a single adaptive network, one that, under sustained load, can become highly sensitised.

Recalibrating the stress response

Depending on the individual, this may include practices that support autonomic flexibility – such as structured breathwork, mindfulness-based practices, graded exposure, or vagal toning exercises. It may also include other physiological interventions to improve systemic resilience, such as nutritional and supplemental support to ensure the right co-factors and building blocks for metabolic activity, detoxification and immune boosting therapies to address toxic or pathogenic overload, lifestyle interventions such as exercise, sleep and circadian rhythm regulation to improve vascularisation, digestive and neuroendocrine functions. These strategies are designed to help the nervous and immune systems regain adaptive range.

Thank you for reading.

Warmest wishes,

Kirkland Newman, Founder, MindHealth360

🌱 Your guide to root-cause mental health.

• See Stephen Porges’ session Embodied Regulation: A Polyvagal Model of Fascia and Autonomic Integration, at this year’s Integrative Medicine for Mental Health (IMMH) Conference – 4 days, 50+ speakers, up to 40 CE credits, exploring integrative medicine psychiatry and root-cause approaches to mental health
• The MindHealth360 Show – Subscribe for evidence-based conversations with leading clinicians and researchers, delivered to your inbox 🎧
• Join the community – Ongoing insights, events and conversations shaping the field. Plus, free content when you sign up to the newsletter ✉️

Further Reading

For readers who would like to explore the science behind the concepts discussed in this article:

Psychoneuroimmunology & Inflammation in Mood Disorders
Miller AH, et al. (2021). Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression.
https://pmc.ncbi.nlm.nih.gov/articles/PMC2680424/

Gut–Brain Axis & Neuroinflammation
Kearns R, et al. (2024). Gut–Brain Axis and Neuroinflammation: The Role of Gut Permeability in Neurological Disease.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11461658/

Cerebral Perfusion & Post-Viral Syndromes
Mohammadi S, et al. (2024). Brain Perfusion Alterations in COVID-19 and Long COVID.
https://onlinelibrary.wiley.com/doi/full/10.1002/brx2.70007

Polyvagal Theory & Autonomic Regulation
Porges SW. Polyvagal Theory: A Science of Safety.
https://www.polyvagalinstitute.org/whatispolyvagaltheory

The Cell Danger Response
Naviaux RK. (2014). Metabolic Features of the Cell Danger Response.
https://www.sciencedirect.com/science/article/pii/S1567724913002390

The post Why The Nervous System Gets ‘Stuck’: Amygdala, Limbic System and the Stress Response appeared first on MindHealth360.

In my recent conversation with psychiatrist Dr William Van Derveer on The MindHealth360 Show, we explored a far more grounded and clinically useful perspective. Rather than positioning psychedelics as a miracle cure, Dr Van Derveer places them within a broader healing model that includes trauma, attachment, inflammation, gut health, lifestyle, spirituality and the deeper biological drivers of mental ill health. 

It is an approach that feels especially relevant now. As interest in psychedelic treatment accelerates, what is needed is not more hype, but more nuance. Not a search for the next silver bullet, but a deeper understanding of how mental health recovery actually works. 

Moving beyond the limits of conventional psychiatry 

One of the most interesting aspects of Dr Van Derveer’s work is the path that led him beyond conventional psychiatry. In our conversation, he described how the limits of medication and talk therapy pushed him to look more closely at the broader terrain of mental illness and recovery. 

This is a tension that many clinicians and patients will recognise. Conventional approaches can be essential and at times lifesaving, but they are not always enough for people whose mental health symptoms are being driven by multiple overlapping factors. When trauma, inflammation, gut dysfunction, nervous system dysregulation, immune imbalance and chronic stress are all part of the picture, symptom suppression alone may leave the deeper causes untouched. 

What emerged from our conversation was a much wider map of care: one that looks not only at thoughts, emotions and diagnoses, but also at biochemistry, physiology, attachment, lifestyle and meaning. The whole person lens integrative mental health calls for. 

Why functional medicine and psychedelic therapy may need each other 

A central theme in my discussion with Dr Van Derveer was that functional medicine and psychedelic therapy are often best understood as complementary. 

Functional medicine helps identify and address the biological terrain that may be shaping mental health: inflammation, nutritional deficiencies, microbiome disruption, immune dysregulation, toxic load and poor stress resilience. Psychedelic therapy, by contrast, may help people access deep emotional material, trauma, insight, self-compassion and spiritual experience in ways that are not always possible through ordinary therapeutic processes alone. 

For many people, these dimensions are deeply intertwined. 

A person may have profound psychological insight during psychedelic therapy, but still struggle to sustain change if they return to a body that is inflamed, exhausted, dysregulated or depleted. Equally, someone may improve their physiology significantly, but remain stuck in deeply patterned trauma responses, relational wounds or destructive beliefs. What Dr Van Derveer describes is a model in which both biology and biography matter. 

That is one of the strongest ideas from our conversation: recovery is often not either biological or psychological, but both. 

Trauma is not only psychological, but physiological 

Trauma is often misunderstood as something that exists only in conscious memory. In reality, as Dr Van Derveer explains, it may be stored outside narrative awareness, including in somatic, episodic and procedural memory. 

This has important implications. Many people cannot easily explain why they feel the way they do, yet their nervous system, beliefs and behaviours may still be shaped by earlier experiences. Early attachment patterns and chronic dysregulation can influence not only relationships and emotional responses, but also inflammation, health behaviours and vulnerability to illness over time.  

Psychedelic therapy may help people access this deeper material, but it does not replace the need for careful therapeutic support. Without integration and context, there is a risk of reducing complex healing processes to a single intervention. 

Psychedelics are not a cure, but a catalyst 

Public conversations about psychedelics often overlook an important distinction: these treatments are not cures in themselves. 

As Dr Van Derveer emphasised, their value lies in their potential to act as catalysts. They may open access to insight, emotional processing and self-compassion. They may create opportunities for behaviour change and new perspectives. But they do not remove the need for ongoing therapeutic work, physiological support and meaningful changes in how a person lives. 

Different compounds also play different roles. MDMA, ketamine and psilocybin each have distinct biochemical and psychological effects, and are suited to different contexts. A more mature understanding of psychedelic therapy requires this level of nuance, rather than treating all compounds or experiences as interchangeable. 

Ultimately, the effectiveness of these treatments depends on what surrounds them. Insight alone is rarely sufficient. Lasting change tends to emerge when psychological work, biological support and lifestyle shifts are brought together. 

A broader model of mental health care 

What becomes clear from this conversation is that the future of mental health care will depend on more integrated ways of thinking. Approaches that do not separate trauma from physiology, or biology from lived experience, but recognise how these layers interact.  

Dr Van Derveer’s perspective reflects a growing shift towards understanding mental ill health as the result of multiple, interacting drivers. Addressing those drivers requires more than a single modality. It requires a framework that is capable of holding complexity while still offering practical pathways to healing. 

This is where psychedelic therapy may have a role, not as a standalone solution, but as part of a wider system of care that addresses root causes and supports long-term change. 

Listen to my conversation with Dr William Van Derveer on The MindHealth360 Show to explore how these approaches may work together in practice.

Thank you for reading.
Warmest wishes,  

Kirkland Newman, Founder, MindHealth360 

🌱 Your guide to root-cause mental health. 

• The MindHealth360 Show – Subscribe for evidence-based conversations with leading clinicians and researchers, delivered to your inbox 🎧  

• Integrative Medicine for Mental Health (IMMH) 2026 Conference – 4 days, 50+ speakers, up to 40 CE credits, exploring integrative medicine psychiatry and root-cause approaches to mental health ✉️ 

• Join the community – Ongoing insights, events and conversations shaping the field. Plus, free content when you sign up to the newsletter. 

The post Psychedelic therapy and functional medicine: a new approach to mental health appeared first on MindHealth360.