Stress and Resiliency – Part 1: A Physiological Point of View

By Arden O'Connor

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This is Part 1 of a two-part article on the effects of chronic stress and building resiliency against stress. Part one explores the physiological effects of chronic stress on the body and brain. Part 2 will discuss the role of resiliency in protecting against chronic stress and explore ways to build resiliency.


Historical Presentation of Stress

Stress affects everyone in different ways. Some are better able to manage stress than others and stress does not discriminate who it affects. Stress manifests itself not only emotionally or mentally, but physiologically as well. Stress came about back in an age where humans needed to respond to the threat of a lion or other wild animal endangering their lives. In today’s society, the majority of the time we are no longer plagued by the threat of attack from a lion but by everyday stressors that take the form of psychological and social disruptions (Sapolsky, 2004). These disruptions can be everyday occurrences such as missing a meeting, waking up late to your alarm, or not getting enough sleep. When our bodies become stressed there are many physiological processes that begin to occur if the stress response does not subside.

Sapolsky (2004) discusses how during a stressful event our sympathetic nervous system is activated which causes many bodily systems to shut down in order to focus energy, and blood, to the areas that need it. Once our bodies have stopped the processes to store excess energy or digest our last meal, nutrients are released into the blood stream to be used. Stress hormones such as glucocorticoids, glucagon, epinephrine, and norepinephrine are released, causing a breakdown of fat cells, glycogen, and protein (Sapolsky, 2004). This means that fatty acids, glucose, and amino acids are flowing freely in the circulatory system waiting to be used by our muscles to run away from an imminent threat. If there is no lion that needs to be run away from, however, the excess energy in our blood stream does not get used, and the body will begin to tire more easily.

Stress Affects Resilience

The more susceptible a person is to stress, the less resilient they tend to be. Masten and Wright (2010) write that “[severity] and chronicity of…adversity [is] important because there is a dose-response gradient, in which higher exposure or worse adversity is related to worse adaptive function on average among a group of people exposed” (p. 220). In other words, the more stressors an individual is exposed to, or the amount of time to which they are exposed, can decrease their resilience. Due to the plasticity of our brains, they have the ability to be changed. Like a muscle, when our brain is used, those neural connections strengthen and quicken, and the ones that are not in regular use will be lost (Southwick & Charney). If our brain is enduring constant stress or adversity, eventually the brain will become more efficient at detecting the stressor. This efficiency leads to an individual that is more susceptible to stressors. If an individuals brain has been ‘programmed’ to respond to stressful situations more readily, it will be much more difficult to bounce back or be resilient. Once the brain is trained to do one thing, it takes even more effort to undue that process and trains it to do something else.

Stress Causing Illness

Another problem that can occur from persistent activation of the stress-response system is health issues such as heart disease and even diabetes. Due to the blood vessels constricting to push more blood to the places in the body that need it during stress, the vessels, eventually, will begin to damage and inflame. If there are fatty acids and glucose constantly circulating, they can attach themselves to a damaged blood vessel causing atherosclerosis, plaque builds up in the arteries and can lead to heart disease (Sapolsky, 2004). Additionally, the hormone insulin is used to stimulate the transport and storage of fatty acids, glucose, and amino acids and convert them into target cells (Sapolsky, 2004). If you are constantly activating the stress response system, over time insulin becomes less responsive and in some cases, can stop responding all together leading to diabetes. Similarly, obesity causes the same health issues. Obesity can be physically and mentally stressful for individuals, and they can be caught in a vicious cycle; overeating due to stress and then feeling stressed because of weight gain.

Stress and Adolescents

Some functions that may be affected by stress are: emotion regulation, “mood regulation, impulse control, judgment, moral reasoning, and acquiring left-hemisphere academic skills that are enhanced by a regulated right hemisphere…” (Montgomery, 2013). For adolescents, these functions are already immature due to the underdevelopment of their prefrontal cortex, the part of the brain right behind the forehead. Stress amplifies impulsivity and lack of emotion regulation, which can cause problems such as susceptibility to drugs and alcohol. Adolescents are preoccupied with fitting in, doing well in school, getting along with their parents, and numerous other potentially stressful situations. On the other hand, the plasticity of adolescent brains also makes them resilient.



Masten, A. S., & Wright, M. O. (2010). Resilience over the lifespan: developmental perspectives on

resistance, recovery, and transformation. resistance, recovery, and transformation. In Reich,

J. W., Zautra,J., & Hall, J. S. (Eds.) Handbook of adult resilience (213-237). New York, N.Y.: The


Montgomery, A. (2013). Neurobiology Essentials for clinicians: what every therapist

needs to know. New York, NY: W. W. Norton & Company.

Sapolsky, R. M. (2004). Why zebras don’t get ulcers (3rd edition). New York, NY: St.

Martin’s Press.

Southwick, S. M., & Charney, D. S. (2012). Resilience: The science of mastering life’s

greatest challenges. New York, NY: Cambridge University Press.

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