How Trauma Affects the Brain & Body

Trauma & Safety

A simple illustration representing psychological safety focused on a single person. The image shows an individual sitting in a relaxed position, surrounded by a soft, warm glow indicating a sense of safety and comfort. The background is minimalistic with soft colours. The person has a calm and content expression, symbolizing trust and openness. There is a sense of personal peace and well-being.

Trauma, defined as any event or series of events that overwhelms an individual’s ability to cope, casts a profound shadow over our lives, affecting not only our mental and emotional well-being but also leaving a lasting imprint on our physical health (APA, 2017).

At the core of our existence lies the need for safety. It is within the context of our resources that we find the stability necessary to navigate life’s challenges. Resources include mutual relationships and physical needs for survival. The need for safety is especially vital in children as they cannot provide their own resources; they really on adults (parents and caregivers). Their feelings of safety and security is solely dependent on adults. When trauma infiltrates our lives, it undermines this sense of safety, leaving us feeling vulnerable and stripped of control. This disruption creates a ripple effect, intertwining with the body’s stress response system in complex ways.

Stress Demand VS. Our Resources – the need for Equilibrium

Stress, a frequent companion of trauma characterized by a demand that exceeds our available resources, disrupts the delicate equilibrium of our physiological systems. It acts as a trigger, setting off changes in our DNA known as DNA methylation, and causing our telomeres, the protective caps on our chromosomes, to shorten faster. These changes are crucial for our cells’ health and stability. Studies have shown a clear link between experiencing trauma and these alterations in our DNA, which can lead to quicker aging at a cellular level. Understanding this connection helps shed light on why those who have experienced trauma might face health issues earlier in life.

On the other hand, within the realm of this stress x resource equilibrium that resilience can be cultivated. Research indicates that exposure to manageable levels of stress can actually bolster resilience over time (Rutter, 2012). However, trauma disrupts this process, skewing the balance and imposing a heavy burden on the body’s stress response mechanisms.

Trauma Dosage: A Critical Factor

The extent and duration of trauma exposure, often referred to as “trauma dosage,” play a pivotal role in shaping its impact on the body. Studies underscore the direct interaction between trauma dosage, age at exposure, and the passage of time (Shonkoff et al., 2009). The cumulative effect of stress and trauma, known as allostatic load, exacts a toll on our bodies, contributing to wear and tear over time.

Childhood Trauma & The Crucial Role of Attachment

For children, the impact of trauma is magnified, as they rely on caregivers for safety and regulation. Adverse childhood experiences (ACEs) can have profound and enduring effects on brain development, shaping synaptic pruning and laying the foundation for future mental and physical health challenges.

Small “t” traumas, though seemingly insignificant when compared to major life-altering events, can have profound and lasting effects on children’s development and well-being. These minor yet pervasive stressors, ranging from parental divorce to academic pressures, have been shown to proliferate and accumulate over time, exerting a cumulative toll on children’s mental health and resilience. Research by Finkelhor et al. (2009), highlights the prevalence of small “t” traumas in childhood, emphasizing their significance in shaping long-term outcomes. Furthermore, studies have underscored the adverse impact of small “t” traumas on various domains of children’s functioning, including emotional regulation, cognitive development, and social relationships (Briggs-Gowan et al., 2010; McLaughlin et al., 2012).  fMRI research by Hanson et al. (2015) has revealed alterations in brain regions implicated in emotion processing and regulation, such as the amygdala and prefrontal cortex, among children exposed to chronic stressors. Additionally, structural MRI studies have demonstrated changes in brain morphology, including alterations in grey matter volume and white matter integrity, in children with a history of early-life adversity (Teicher et al., 2016).

The Mind and Body

The flight or fight response is a primal physiological reaction to perceived threats or danger. When confronted with a threat, the body’s sympathetic nervous system activates, releasing hormones such as adrenaline and cortisol. These hormones prepare the body for action, triggering a cascade of physiological changes aimed at enhancing survival.

In the context of trauma, the flight or fight response can become dysregulated, leading to chronic hypervigilance, exaggerated startle responses, and heightened anxiety. This hyperarousal can manifest as a persistent state of readiness for danger, even in non-threatening situations, further exacerbating the impact of trauma on both the body and mind.

Trauma disrupts our ability to perceive and interpret internal bodily sensations, a process known as interoception. This impairment extends beyond mere bodily awareness, influencing attention, empathy, cognition, and emotional regulation. Additionally, trauma alters the functioning of key brain regions involved in processing threat cues and regulating emotional responses. Research by Critchley and Harrison (2013) has shown that trauma significantly impacts interoception, particularly affecting the person’s ability to detect their internal states, such as heartbeat. This disruption in interoception influences various aspects of cognition, emotion, and self-awareness.

Neuroimaging studies have elucidated alterations in specific brain regions associated with trauma. The thalamus, acting as a ‘gatekeeper,’ assesses incoming information for threats and passes them to the amygdala, the brain’s ‘alarm centre’ (LeDoux, 2000). If the amygdala perceives a threat, it triggers the release of stress hormones, preparing the body for fight, flight, freeze, submit, or dissociate responses (Critchley & Harrison, 2013). Meanwhile, the hippocampus, akin to a filing clerk, compares the amygdala’s assessment with past experiences, determining whether the perceived threat is valid and regulating the body’s response accordingly (Bremner et al., 2005).

Studies have demonstrated hyperactivity in the right anterior amygdala and underactivity in the dorsal anterior cingulate and medial prefrontal cortex during re-experiencing trauma, while experiencing dissociation shows hyperactivity in the dorsal anterior cingulate and medial prefrontal cortex and underactivity in the right anterior amygdala (Critchley & Harrison, 2013).

The physiological repercussions of trauma extend to every system in the body. From alterations in heart rate variability to dysregulation of the vagus nerve and the endocrine system, trauma casts a wide net, impacting everything from digestion and immune function to reproductive health and aging processes.

Treatment Pathways

While the impact of trauma on the body is profound, there is hope in the realm of treatment. Evidence-based approaches such as cognitive-behavioural therapy (CBT) (Ehlers et al., 2013), somatic experiencing therapy (Payne et al., 2015), and eye movement desensitization and reprocessing (EMDR) (Shapiro, 2014) offer promising pathways to healing. Additionally, practices such as mindfulness (Khoury et al., 2013) and transcendental meditation (Orme-Johnson et al., 2010) show potential in mitigating the physiological effects of trauma.

TMS, a non-invasive procedure that utilises magnetic fields to stimulate specific regions of the brain, has shown promise in modulating neural circuits implicated in trauma processing and regulation of emotional responses. Preliminary studies have demonstrated the efficacy of repetitive TMS (rTMS) in reducing symptoms of post-traumatic stress disorder (PTSD) and depression, both of which commonly co-occur with trauma exposure (Philip et al., 2016). Similarly, other forms of electromagnetic stimulation, such as transcranial Direct Current Stimulation (tDCS) and Deep Transcranial Magnetic Stimulation (dTMS), have also been explored as potential adjunctive treatments for trauma-related disorders. These techniques hold the potential to target specific brain regions involved in fear extinction and emotional regulation, offering a novel approach to augment traditional psychotherapeutic interventions.

Written by Weronika, Smart TMS Edinburgh clinic

References:

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