The latest findings on trauma, stress & resilience: neurobiology of the brain explains pathways in post-traumatic stress disorder and stress management.

Neurobiology and trauma: how the brain and immune system suffer from post-traumatic stress disorder and stress - and how significant disruption can lead to resilience

Traumatic experiences leave traces - not only in the soul, but also in the nervous system, the immune system and in the functional and structural architecture of the brain. This is not about simplistic assertions such as Bessel van der Kolk's much-quoted but scientifically controversial slogan "The body keeps the score". This formula suggests a symbolic inscription of trauma in the body without explaining precisely on which physiological, neurological or immunological level this storage allegedly takes place. Such a metaphorically charged representation often replaces differentiated analysis with suggestive imagery - which tends to stand in the way of serious neurobiological analysis.

Current research, on the other hand, shows that Stressful experiences, especially in early childhood or under conditions of repeated helplessness, have been shown to influence neuronal maturation, the stress response system, the hormonal and immune systems and even the epigenetic expression of certain genes. Structures such as the amygdala, hippocampus and prefrontal cortex change in size, function and connectivity. The balance of stress hormones such as cortisol and noradrenaline is permanently disrupted. The neuronal circuitry is programmed to "alarm" - with long-term consequences for affect regulation, memory, behaviour and susceptibility to illness.

The neurobiology of trauma not only offers a more precise understanding of the disorder, but also opens up new therapeutic and preventive possibilities.

What it's about:

how trauma changes the brain structurally and functionally

why the immune system overreacts to stress

how resilience is built up psychologically and biologically

What stress reactions do to the cortex, hippocampus & co. and what happens cognitively and neurobiologically during a psychologically traumatic experience

Gladly - here is a comprehensively revised and more in-depth version of both sections in a coherent style, suitable for a professionally informed but generally understandable blog post:

Which areas of the brain are particularly affected by trauma?

Traumatic experiences change the brain - not only functionally, but also measurably in its structure. Three closely interconnected regions are particularly affected: The amygdala, hippocampus and prefrontal cortex. Together, these form a central network for processing emotions, threat judgements, memories and action control.

The amygdala, the brain's "alarm centre", registers potential dangers and plays a key role in triggering the stress response. In people with post-traumatic stress disorder (PTSD), the amygdala is often permanently overactive. It fires even when there is no real threat - with the result that even neutral stimuli are perceived as dangerous.

The hippocampus, which is responsible for contextual categorisation and memory formation, has been shown to shrink under chronic stress. Persistently high cortisol levels - typical after a trauma - impair neurogenesis in this region. As a result, memories are harder to integrate and the difference between "then" and "now" becomes blurred. This explains why many traumatic memories are experienced as intrusive and present, even though the event has long since passed.

Finally, the prefrontal cortex is responsible for impulse control, cognitive evaluation and the conscious regulation of emotions. After traumatic experiences, this area often becomes functionally underactive. Imaging techniques show that while the amygdala overreacts, activity in the prefrontal cortex is reduced. This imbalance weakens the ability to self-regulate, makes it difficult to understand one's own reactions and promotes reactive, defensive behavioural patterns.

In addition to these three core regions, other networks are also affected depending on the individual's disposition - such as the default mode network, which is responsible for processing the self and autobiographical memories. Neurobiologically, this results in a finely tuned but vulnerable system whose balance can be permanently disrupted by overwhelming experiences.

What role does the amygdala play in the stress response?

The amygdala is considered the brain's early warning system. It constantly scans the environment for potential dangers and triggers a stress response within milliseconds of a perceived threat - even before the prefrontal cortex can make a conscious assessment. In evolutionary terms, this was essential for survival. In a chronically activated state, however, it is precisely this mechanism that becomes a problem.

In post-traumatic stress disorder, neuroimaging studies show significantly increased amygdala activity - not only with confronting stimuli, but also at rest. This overactivation leads to a generalised state of alert: people react to unexpected noises, social situations or certain images with massive tension, even though there is no objective danger.

In addition, the amygdala stores emotional "labels", i.e. the emotional quality of a memory, not its context. Without the counterbalance provided by the hippocampus and the prefrontal cortex, stimulus processing remains fragmented. This is why traumatic memories often appear as sensually intrusive "flashes" - without temporal classification, but with a high affective charge.

This neuronal constellation - an overreactive amygdala with a simultaneously inhibited cortex - leads to those affected feeling at the mercy of their reactions. The ability to relativise stressful stimuli or to calm down internally is limited. This is precisely where many therapeutic methods come in: They strengthen cortical control and enable the brain to categorise threat signals more realistically - through new neuronal circuits and conscious regulation.

How acute stress turns into chronic stress - and what happens in the body in the process

Acute stress is an evolutionarily sensible reaction to threat: the autonomic nervous system is activated, stress hormones such as cortisol and noradrenaline are released, alertness increases, the sensation of pain decreases - the body switches to survival. As soon as the threat has passed, this system normally regulates itself back down again.

In the case of traumatic experiences, however, this regulatory mechanism becomes unbalanced. This is particularly true if the situation was experienced as overwhelming or if an escape or defence reaction was not possible. In such cases, the physiological alertness remains - the stress response "freezes". As a result, the stress system is chronically activated, which becomes a permanent burden on the body and psyche.

The HPA axis (hypothalamus-pituitary-adrenal cortex) plays a key role here: it controls the release of cortisol, which under normal conditions brings the body back to a state of rest. In people with post-traumatic stress disorder (PTSD), however, studies show a dysregulation of this axis. Cortisol levels can be permanently increased or - paradoxically - decreased, both of which are associated with health risks. In either case, the organism remains in a "guarded position", which has an exhausting and pathogenic effect in the long term.

Early childhood stress and the mechanism of later stress disorders

Early stress - for example due to emotional neglect, violence, unstable relationships or severe experiences of loss - affects a brain that is still developing. Important neuronal networks are under construction during childhood in particular: the limbic system, the prefrontal cortex and the connection between the two. Chronic stress during this time therefore has a particularly strong effect.

Long-term studies and meta-analyses show that early childhood trauma significantly increases the risk of later PTSD, depressive disorders, anxiety disorders and personality disorders. This correlation can be explained not only psychologically, but also neurobiologically: stress hormones interfere with synapse formation, serotonin regulation and neuronal plasticity. The brain learns for survival - not for safety, relationships or self-control.

What is particularly problematic is that chronic stressors can permanently weaken the ability to regulate emotions. The prefrontal cortex develops under restricted conditions, while the amygdala is over-activated. The neuronal network remains incomplete. This results in increased vulnerability - a so-called vulnerability mechanism, which can also lead to an excessive stress response in the event of subsequent stress.

The long-term consequences of trauma and stress on the immune system

In addition to the brain, the immune system is also heavily involved in the consequences of chronic stress. In psychoneuroimmunology, this is referred to as an "inflammatory phenotype": people who have experienced trauma often show increased levels of inflammatory markers such as interleukin-6 (IL-6), TNF-alpha or C-reactive protein (CRP). These processes often go unnoticed - but not without consequences.

Chronic inflammatory conditions are associated with a variety of somatic diseases: Cardiovascular disease, type II diabetes, autoimmune diseases, chronic pain - but also with mental illnesses such as major depression. The body does not react to a real infection, but to the biological signature of a permanently perceived threat.

The connection between the psyche and the body is particularly clear here: traumas do not leave a symbolic "memory", but affect the metabolism, the nervous system and the organ systems via neuroimmunological mechanisms. Those who carry trauma in their biography not only have an increased risk of mental disorders, but also of immune system dysregulation, which favours physical disease processes.

Gladly - here is the comprehensively expanded version of the section:

The brain and genetic or epigenetic risk factors

Both genetic predispositions and epigenetic changes play a significant role in the development and maintenance of post-traumatic stress reactions. This is particularly evident in people who have had traumatic experiences in their childhood, such as abuse, neglect or chronic attachment stress (so-called childhood trauma). In such cases, an increased susceptibility to stress can be reflected in the biological response systems throughout life.

A key genetic risk factor is the so-called 5-HTTLPR polymorphism in the promoter region of the gene that codes for the serotonin transporter. This gene variant influences how quickly serotonin - an important neurotransmitter for emotion regulation - is transported from the synaptic cleft back into the nerve cell. Studies show, , that people with the so-called "short allele" variant react more frequently in stressful situations with excessive stress reactions and a higher risk of PTSD or depression. The genetic make-up acts as an amplifier here, not a cause: without stressful environmental influences, the risk often does not materialise.

Furthermore, epigenetic mechanisms show how early life experiences intervene in biological regulation. Epigenetics refers to changes in gene activity - for example through the methylation of certain DNA segments - without the underlying genetic sequence being altered. Such changes can lead to genes that actually regulate stress buffers or immune responses being weakened or overactivated. In the context of early trauma in particular, such epigenetic imprinting can be detected, for example in the reduced expression of glucocorticoid receptors, which normally help to dampen the release of cortisol.

It is important to note that genes alone do not determine anything. Rather, psychological vulnerability arises from the interplay of genetic make-up, psychosocial environment, protective factors and individual processing. A genetic or epigenetic predisposition is therefore not automatic - but an increased risk background that can be strengthened or weakened by life events, resources and therapeutic support.

What does "resilience" mean in a neurobiological context?

Resilience describes a person's ability to remain mentally stable despite adverse circumstances or traumatic experiences or to recover after stress. In a neurobiological sense, resilience means more than just mental resilience - it manifests itself at the level of the nervous system, stress regulation and even cellular gene activity.

A resilient nervous system reacts flexibly to stressors: it activates appropriately in the event of danger - for example by releasing cortisol and noradrenaline - but quickly returns to a resting state once the threat has subsided. It is precisely this ability to regulate stress that distinguishes resilient people from vulnerable people. In people with increased resilience, the activation of the amygdala remains more moderate in response to emotional stimuli; at the same time, they show greater involvement of the prefrontal cortex, which has an inhibitory effect on emotional overreactions.

From a neurobiological perspective, resilience is therefore not an innate state, but the result of a complex interplay of neuronal plasticity, neuroendocrine balance and lifelong learning experiences. Studies show that more resilient people react to psychosocial stress with more stable cortisol profiles, a lower tendency to inflammation and higher heart rate variability (as a marker for vagal self-regulation).

Initial research also indicates that resilience may also be linked to epigenetic protective mechanisms: Certain genes associated with stress processing and affect regulation appear to be more "favourably" regulated in resilient individuals - that is: more strongly activated or more effectively controlled.

The importance of resilience lies in the fact that it is not only psychologically effective, but also measurably neurobiologically effective. It does not protect against stress or trauma - but it does protect against their long-term negative effects on the brain, immune system and mental stability. And: resilience can be promoted - through secure attachments, physical activity, self-efficacy, social integration and targeted therapeutic intervention.

Of course - here is the extended section with integration of psychodynamic trauma therapy as an independent and important approach:

What helps therapeutically with chronic stress and stress disorder?

Chronic stress is not just a burden, but a state of profound neurobiological dysregulation. Targeted therapeutic interventions are required to bring the nervous system out of a permanent alarm mode and back into a regulated equilibrium. In modern psychiatry and psychotherapy, various methods are available for this purpose, which work on different levels - cognitive, physical, emotional and physiological.

1. trauma-focussed psychotherapy

Psychodynamic trauma therapy focuses on understanding unconscious conflicts that have been activated or reactivated by traumatic experiences. It views trauma not only as an external event, but also as an internal psychological event that is related to previous attachment experiences. The transference dynamic is central here, which can be consciously experienced and worked on in the therapeutic relationship.

Psychodynamic methods offer space to reflect on implicit affects, shame, guilt, defence mechanisms and early self-images in dialogue. The primary focus is not on symptomatic relief, but on the integration of split-off inner states - a process that can sustainably strengthen both self-structure and emotional regulation. Newer approaches such as mentalisation-based therapy or depth psychology-based psychotherapy with a trauma-focused orientation represent important further developments in this area.

Trauma-focused cognitive behavioural therapy is also central, particularly with exposure and confrontation elements. It helps to process trauma-related thoughts and memories, question dysfunctional beliefs and develop new strategies for regulating emotions and stress.

2 EMDR (Eye Movement Desensitisation and Reprocessing)

EMDR works with bilateral stimulation to process fragmented memories. It is particularly effective for PTSD based on evidence and has been proven to relieve the limbic system and reactivate cortical processing mechanisms.

3. mindfulness-based methods

Mindfulness training promotes conscious awareness of inner processes and interrupts automatic reaction patterns. This strengthens affect regulation, lowers physiological stress parameters and can protect against relapses.

4. body-orientated approaches to self-regulation

Body-based methods such as Somatic Experiencing, trauma-sensitive yoga or focussing have a direct effect on the autonomic nervous system. They help to make implicit body memories accessible and to gradually release chronically activated protective reactions (e.g. numbness, flight impulses).

These methods work on different levels - from cognitive re-evaluation to non-verbal processing - and therefore offer a variety of approaches for people with chronic stress or post-traumatic stress. The decisive factor is not the choice of a single method, but rather the adaptation to the individual experience, the security of attachment in therapy and continuous stabilisation in everyday life. This is the only way to achieve sustainable healing.

Here is the comprehensively revised and more in-depth version of this section:

How can resilience be strengthened - and the immune system regulated?

Resilience is not just a psychological characteristic, but a dynamic process - an ability that can be developed, strengthened and promoted through targeted measures. From a neurobiological perspective, resilience means that the nervous system reacts flexibly and adaptively to stress: It activates protective mechanisms in the short term in the event of acute stress, but quickly returns to a regulated state. The more successful this return is, the lower the risk of chronic overload or somatic secondary illnesses.

What strengthens resilience?

Research shows that there are a number of protective factors that have been proven to contribute to the development and maintenance of resilience - both on an individual and systemic level:

Social support and secure attachments: The most important resilience factor is the experience of emotional security. Stable relationships - whether familial, friendly or therapeutic - promote emotional co-regulation, provide support in crises and strengthen the psychophysiological ability to self-regulate. Bonding activates calming networks in the brain and has a stress-reducing effect.

Regular exercise and healthy sleep patterns: Physical activity has been shown to reduce the release of stress hormones, improve the neurovascular supply to the brain and support the release of mood-boosting neurotransmitters such as serotonin and dopamine. Sleep quality is also crucial: chronic sleep deprivation impairs the emotional stimulus threshold, increases cortisol levels and weakens the immune defence.

Stress reduction through relaxation techniques: Grounding, e.g. breathing techniques, progressive muscle relaxation, yoga, meditation or even nature-based routines such as walks in the forest activate the parasympathetic branch of the autonomic nervous system - and signal to the body: it's safe. This measurably reduces the duration and intensity of the stress response.

Building self-efficacy and cognitive flexibility: People who experience themselves as capable of acting develop a more robust stress profile. This includes the ability to interpret challenges as manageable, to develop solutions and to adopt new perspectives. Cognitive flexibility - i.e. the ability to switch between different inner attitudes - is considered a key marker of psychological adaptability.

How can the immune system be specifically regulated?

Resilience and immune balance are closely linked. Chronic stress leads to an increased release of pro-inflammatory cytokines - which not only undermines mental stability in the long term, but also physical health. It is therefore crucial to intervene in a targeted manner at the level of the body:

Balanced, anti-inflammatory diet: a diet rich in omega-3 fatty acids, antioxidants, fibre and micronutrients supports the gut lining, reduces silent inflammation and boosts immune function. Highly processed foods, sugar and trans fats, on the other hand, favour inflammatory processes.

Exercise as an immune modulator: Regular physical activity acts like a biological reset button: it lowers chronic inflammation levels, promotes circadian rhythms and strengthens vagal control - a key mechanism for dampening excessive stress responses.

Therapeutic regulation of stress axes: In therapy - especially for chronically stressed or traumatised people - it is crucial to sustainably reduce the reactivity of the HPA axis (hypothalamus-pituitary-adrenal cortex). The aim is to achieve a balance between tension and relaxation, between activation and withdrawal.

Resilience is not an innate characteristic, but a biologically based adaptation system that can be strengthened through experience, relationships, exercise, nutrition and inner attitude. Those who promote resilience not only strengthen the psyche - but also the immune system, self-awareness and the ability to regenerate after stress.

Key findings at a glance:

Trauma influences the brain, immune system and behaviour in complex ways

The amygdala, cortex and hippocampus are particularly affected neurobiologically

Resilience is the ability to regulate the neurobiological consequences of stress

Genetic and epigenetic factors influence how we process trauma

Therapeutically effective approaches can calm the nervous system and stabilise the psyche

Resilience in the context of trauma requires social, physical and psychological resources

Prevention by strengthening stress management strategies is crucial