Missed Part 1 of our series “Breaking the taboo of neuro-mental health”? Read on here.
We just discovered that 1 in 8 individuals worldwide is affected by neuro-mental conditions. Hence you, or someone close to you, is probably suffering right now.
This was the dramatic statement we left you with at the end of our first instalment on neuro-mental health.
So, while most of us may be spared a psychosis, we are nevertheless all susceptible to neuro-mental issues. Why is that?
Because every human being experiences stress and/or trauma at some point in their lives – whether episodically or chronically.
Beginning with the brutality of birth and all the way to a more or less protracted death, the seasons of human life are punctuated by stress and trauma. In fact, as we will discover in our next instalment, both stress and trauma can already be acquired in utero. But perhaps even more disturbing, the epigenetic signature of a trauma may be transmitted over at least three generations. Hence, you may be carrying the imprint of something that did not actually happen to you!
Furthermore, by virtue of their very existence, our bodies are submitted to a permanent if (mostly) low-grade physiological stress – from the passive effects of gravity to the active wear and tear of our daily lives.
In fact, the primary acceptation of the word “stress” is mechanical. While mechanical stress may not be our primary focus here, it provides us with a good basic metaphor for the biopsychosocial stress we wish to investigate.
One of the joys of being a (small) kid is that you get to freely experiment with the endless possibilities offered by the physicality of the material world around you. From building and toppling block towers to climbing trees or designing your first catapult, you gradually get a sense of material resilience and limitations.
In fact, a simple elastic band can provide you with a fascinating lesson on stress, strain and fracture – even without going into the physical laws that govern these phenomena. While eminently resilient, since it regains its shape after most types of pressure/stress, rubber will snap/fracture if you pull/strain it too far.
As you go on experimenting with stress, strain and fracture using other materials, you cannot help but notice very different patterns in the relationship between these variables. Depending on the type and structure of a material, it will be more or less challenging to apply pressure/stress – think eggshell versus steel. Also, the strain interval will vary greatly, e.g. between paper and leather. Finally, the fracture may happen predictably or less so. In this respect, climbing a tree provides a good, if potentially painful, lesson: a thinner but healthy branch may carry your weight more reliably than a much sturdier-looking dead limb.
You may also notice that materials age more or less well, depending on what stressors they have been exposed to and for how long, as well as how the material has been cared for. Even resilient rubber can become brittle and perish, when exposed to too much heat, light, or humidity.
But enough about stuff, what about us? How does stress operate in and affect people?
When exposed to a variety of biopsychosocial stressors, our human biology operates along similar principles to those of the materials we just described.
Indeed, depending on type, dosage, duration and combination as well as on a person’s current psychophysiological state and resources, stressors can have very different effects on different people at different times. Stress can be beneficial, stimulating resilience and creativity, or it can lead to disease and death− as well as all manner of in-between states.
However, because human biology is governed through the intertwining and interconnection of several complex systems, the effects of stress and trauma as well as potential remedies have proven rather challenging to investigate.
Paving the way towards understanding the idiosyncrasies of human stress as we perceive it today, were two central historical figures.
Walter Bradford Cannon, an American physiologist, was the first researcher to describe a rough stress scenario – first in animals, then, as an army physician, in soldiers during WWI.
Initially, when organisms were under threat, Cannon observed both a neural response and the release of adrenaline as a reaction to a physical or psychological emergency. These were prerequisites to enter what he described as the “fight or flight” mode.
Today, we still consider the endocrine and the neural aspects as the central actors of stress response, under the guise of the so-called hypothalamic-pituitary-adrenal (or HPA) axis and the activation of the autonomic nervous system. We have also retained Cannon’s fight or flight expression, but “freeze” and “fawn” have been added in subsequent years to the catalogue of potential acute stress responses.
Once the stress had subsided, Cannon noticed that organisms tended to return to a form of functional baseline. This led him enunciate one of the most groundbreaking concepts of modern biology: the idea of homeostasis, based on the notion of “milieu intérieur” [internal environment] developed by Claude Bernard in the mid-19th century. In a nutshell, “homeostasis”can be defined as the way in which a biological entity strives towards balance through self-regulation of its multiple systems for optimal functioning.
As Cannon himself posited it, homeostasis was not a chance occurrence but the result of “organized self-government” (Cannon; 1932). This was to prove the critical distinction between stress management in the biological realm compared to the much simpler stress reaction we described in the material field, i.e. stress, strain and fracture.
So, when a threat occurs, the body will usually steer an adequate reaction by re-distributing resources such as blood flow or glucose release to facilitate an appropriate stress response. But once the threat has passed, the body usually tries to regain homeostasis. Hence, living organisms display a form of resilience when confronted with external threats. This is a good thing, considering the frequent pressures and emergencies they have to contend with over a lifetime. But this elasticity has its limits.
The father of modern stress, Hungarian-Canadian endocrinologist Hans Selye delved even further into stress and its boundaries. As a medical student in the 1930s, he had already noticed that patients with various chronic diseases displayed a set of common symptoms that were not directly related to their condition. Later, he was able to witness that laboratory rats exposed to stressors such as cold, drugs or surgical injury showed similar patterns.
This led Selye to define stress as “the non-specific response of the body to any demand for change” (Selye; 1976). He went on to analyse the physiology of stress as a set of responses which he called the "general adaptation syndrome".
The syndrome was articulated into three phases: in the alarm phase, the body was temporarily overwhelmed (shock) before mobilising its neuroendocrine resources (antishock). In the resistance phase, the body’s response intensified with the added release of glucocorticoids. When stressors did not abate, the exhaustion phase signalled permanent overwhelm. This represented the pathological state, stemming from chronic stress.
The posterity of stress
Building on Selye’s work, in the 1960s and 70s, academic psychologists attempted to qualify and quantify the potential effects of different stressors (such as divorce, illness or retirement) on mental health, through the elaboration of instruments such as the “Life Events and Difficulties Schedule” or the “Holmes and Rahe stress scale”.
In parallel, research was pursued in the neuroendocrine, molecular, and immunological aspects of stress. Stress, especially in its chronic form, was shown to trigger or worsen a variety of physical and mental health issues, from cardiovascular illness to diabetes, through depression and anxiety disorders.
In later years, psychosocial and interactional theories of stress began to emerge, describing the emergence of stress as the consequence of a mismatch between a person, their resources and their environment or, even more subtly, as a discrepancy between a person’s perception of themselves, their resources and the environment.
However, stress did not just take academia by storm. By the end of the 1970s, stress had already outlived its ivory tower destiny. It was increasingly perceived as a broad-based societal phenomenon, affecting potentially everyone through the frenzied pace of modern life enabled by the exponential development of technology. The effects of stress were seen as reverberating through the entire (post-)modern world of work, leisure and relationships. Hence, stress became both a major public health issue and a fixture in popular media.
It was at this point that “trauma” began to rear its now ubiquitous head, as renewed attention turned towards deeply perturbed soldiers as well as abused and neglected children.
Read on about trauma and its impacts on health in our next instalment!
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Sources and further reading
“WHO Special Initiative for Mental Health”. World Health Organization. Online: https://www.who.int/initiatives/who-special-initiative-for-mental-health
Szyf, M. (2019). “The epigenetics of perinatal stress”. Dialogues in Clinical Neuroscience, 21(4), 369–378. doi :10.31887/DCNS.2019.21.4/mszyf. Online : https://www.tandfonline.com/doi/full/10.31887/DCNS.2019.21.4/mszyf#d1e118
Cao-Lei L, Massart R, Suderman MJ, Machnes Z, Elgbeili G, Laplante DP, et al. (2014) "DNA Methylation Signatures Triggered by Prenatal Maternal Stress Exposure to a Natural Disaster: Project Ice Storm". PLoS ONE 9(9): e107653. doi:10.1371/journal.pone.0107653. Online: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0107653
Cooper, Andrea. “Can trauma be inherited through genes?”. National Geographic. June12, 2024. Online: https://www.nationalgeographic.com/premium/article/trauma-genes-inherit-epigenetics-methylation
“Stress History: From Ancient Concepts to Modern Understanding”. Neurolaunch. August18, 2024. Online: https://neurolaunch.com/history-of-stress/
Hutmacher F. “Putting Stress in Historical Context: Why It Is Important That Being Stressed Out Was Not a Way to Be a Person 2,000 Years Ago”. Front Psychol. 2021 Apr 20;12:539799. doi:10.3389/fpsyg.2021.539799. Online: https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2021.539799/full
Bockarova, Mariana. "The History of Stress". Psychology Today. December 29, 2021. Online: https://www.psychologytoday.com/us/blog/romantically-attached/202112/the-history-stress
“8.6: Elasticity, Stress, Strain, and Fracture”. LibreTexts™ PHYSICS. Online: https://phys.libretexts.org/Bookshelves/University_Physics/Physics_(Boundless)/8%3A_Static_Equilibrium_Elasticity_and_Torque/8.6%3A_Elasticity_Stress_Strain_and_Fracture
Vogel, Steven. Living in a physical world XI. To twist or bend when stressed. Journal of biosciences. (2007). 32. 643-55. 10.1007/s12038-007-0064-6. Online: https://www.researchgate.net/publication/6078465_Living_in_a_physical_world_XI_To_twist_or_bend_when_stressed
“Claude Bernard”. Wikipedia. Online: https://fr.wikipedia.org/wiki/Claude_Bernard
“Walter Bradford Cannon“. Wikipedia. Online: https://en.wikipedia.org/wiki/Walter_Bradford_Cannon
“Homeostasis”. Wikipedia. Online: https://en.wikipedia.org/wiki/Homeostasis
Cannon, Walter Bradford. The Wisdom of the Body. New York: W. W. Norton & Company, 1932, pp. 177-201.
Selye, Hans. The Stress of life. New York: McGraw-Hill, 1956.
Selye, Hans. “Stress without Distress”. Psychopathology of human adaptation. Ed. G. Serban. New York: Springer Science + Business Media, 1976, p. 137.
“Stress (biology)”. Wikipedia. Online: https://en.wikipedia.org/wiki/Stress_(biology)
Illustrations
Pavel Danilyuk / pexels
Pezibear / pixabay
Artur Pawlak / pixabay
Septimiu Balica / pixabay
Nataliya Vaitkevich/ pexels
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