The Stress Response
Normally in the wild, stress is used to help one survive from becoming eaten by prey. It is only meant to last for a few minutes and then the stress response naturally shuts down once the stimuli stop. Humans tend to turn on the stress response based on psychological stressors and keep it on. In western society, stress is used to rise to a challenge. There are value and praise for those who are constantly stressed and overworking themselves. Humans do not stress like a normal mammal, because humans do not have to worry about having 30 seconds left of life expectancy. Instead, for most, turning the stress response on too often and for long periods of time causes dangerous psychological stressors. It is stress that causes the real danger and slowly kills the body by initiating disease. The stress response is activated by a stressor, which then knocks the body out of homeostatic balance. If the stressors go on for too long and then disorders develop. (Sapolski, 2017)
Friedman (2015), reports that when fearful stimuli appear the basolateral and central nucleus of the amygdala are activated by which then stimulates the components of the species-specific defense response (SSDR). These SSDRs are instinctual and automatic reactions when fearful events occur. The components that are activated include the autonomic nervous system which regulates certain body processes such as heart rate, digestion, respiratory rate, etc.; neuroendocrine system which includes the hypothalamus, the pituitary glands, and the connection to hormone release and growth (HPA Axis); skeletal muscles which get the body ready for the fight, flight, or freeze behaviors; and changes in information processing such as chronic overgeneralization of threat. (Friedman, 2015)
The central nucleus in the amygdala exchanges messages with the prefrontal cortex (PFC) and can activate dopamine (DA), norepinephrine (NE), and serotonin (5-HT). Friedman (2015) emphasizes that the PFC is the key component that regulates the amygdala. Usually, during low-stress times, the PFC sends out messages to suppress the central nucleus activation of the SSDR. When stress occurs, excessive NE can suppress the PFC signals on the amygdala, therefore causing uncontrollable amygdala activation of the SSDR. DA and 5-HT add to the mess by suppressing the stimulation of certain neurons in the amygdala. Therefore, it is important to find ways to regulate the PFC to optimize the SSDR. (Friedman, 2015)
Chronic exposure to threatening situations activates the fear conditioning and encodes into a cycle of never-ending fear and activation of the amygdala. This can lead someone to have issues with chronic post-traumatic stress or anxiety issues even when danger is not present. Therefore, it is important to find therapies that help to “decrease the amygdala activation and to increase PFC activation”. (Friedman, 2015, p. 12)
PTSD
PTSD is the only major mental health disorder in which a cause is known. The causes are by a "psychologically traumatic environmental event (abuse, hurricane, war, etc.) or any biological abnormality" (medical disorders, physical disabilities, etc.). (Pitman, Rasmusson, Koenen, Shin, Orr, Gilbertson, & Liberzon, 2012, p.1) Psychological trauma can be a result of witnessing an event that is perceived as life-threatening or posed as a serious injury to the self or others. (Sherin & Nemeroff, 2011) Within these experiences fear, horror, and helplessness, are often accompanied by the development of PTSD. The characteristics of PTSD can be grouped into three primary domains. One being reminders of the exposure. This includes flashbacks, intrusive thoughts, nightmares, etc. Second is activation including hyper-arousal, insomnia, agitation, irritability, impulsivity, and anger. And the third deactivation including numbing, avoidance, withdrawal, confusion, dissociation, and depression. (Sherin & Nemeroff, 2011)
Childhood trauma is associated with an increased risk to develop PTSD. There is literature that states that early experiences including prenatal stress and stress throughout childhood have profound and long-lasting effects on the development of the neurobiological systems. (Sherin & Nemeroff, 2011) Physical injury is also connected with psychological trauma and increases the risk of developing PTSD. Other genetic factors can play in the development of PTSD. Genetic studies show that genetic influences accounted for 30 to 70 percent of those to likely develop PTSD. (Pitman, et. al., 2012) Genetic risk factors that are common are depression, GAD, and panic disorder. Genes that affect the risk of developing PTSD also influence the risk of developing other mental disorders. (Pitman, et. al., 2012)
To understand trauma, one must understand it at a biological, organic, cellular, and molecular level. (Pitman, et. al., 2012) The neurobiological changes that are connected to PTSD include changes in learning/delay, hyperarousal, and sporadic dissociative behavior along with the three primary domains mentioned above. (Sherin & Nemeroff, 2011)
Autonomic Nervous System
Within each human being, there is the Autonomic Nervous System (ANS). Within the ANS there is the sympathetic (SNS) and the parasympathetic nervous system (PNS). PNS is when one is at a resting state. The pupils constrict and are smaller, salvation is increased to allow digestion, respiratory rate is decreased or at baseline, and the heart rate slows. There is no glucose release and glucose storage is increased. The adrenal glands decrease in adrenaline and one can digest and be at a calm state in their body. (McCorry, 2007)
However, the SNS is the one that causes changes in the body when afraid, and when the stress response is activated the body gets ready to fight or flight. Pupils dilate to help see better to fight or flee, the lungs respiratory rate increases, the heart rate beats faster, the liver produces glucose to produce energy so that one can fight or run. The adrenal glands stimulate hormones called adrenaline and the GI tract slows down digestion to revert energy to other organs in the body. Chronic psychological stress can lead to stress reduction disorders if one does not properly know how to calm their mind and body down. (McCorry, 2007)
Heart Rate Variability
The effects of prolonged stress and prolonged SNS activation in human beings includes the loss of HRV and an increase in illness. The vagus nerve is important in the regulation of many functions within the body. Vagal activity is reflected in the heart rate variability (HRV). High vagal activity has a high heart rate at rest while having a low resting heart rate leads to vagal withdrawal. (Broschott, Verkuil, & Thayer, 2017) Having a low resting heart rate will not recognize safety and thus activate the generalized perception of unsafety (GU). The GU causes the stress response to remain activated, therefore, the mind and body cannot perceive safety, and there is a focus on constant danger around every corner. Low heart rate and vagal withdrawal can lead to health and mental illness. (Broschott, Verkuil, & Thayer, 2017)
According to the Broschott, Verkuil, & Thayer (2017) article, the low HRV and parasympathetic vagal withdrawal are strongly connected to the PFC-inhibition of subcortical areas. It states that for optimal survival, the disinhibition of the response to threat must be as immediate and fast as possible. (Broschott, Verkuil, & Thayer, 2017)
There is something one can learn from the wild. In Peter Levine’s book Wake the Tiger (1997), he states that the same idea concerning an animal being faced with a threat, triggering its automatic stress response, and the animal either responds in flight, fight, or frozen behavior. It is important to understand how wild animals calm their automatic stress responses down after the threat. According to Levine (1997), if the animal is lucky to not be eaten or killed by its predator, the animal gets up and “discharges all the energy mobilized to negotiate the threat” by shaking it out of its body. (Levine, 1997, pg. 19).
Most humans do not release stress and therefore continue to hold it in and prolong the stress response which then causes dysregulation of the body's functions leading to disease. It is important to find modalities that can help stimulate the human's vagus nerve in order to energize the parasympathetic nervous system which then relaxes the body, turns off the stress response, halting the release of cortisol and adrenaline, and so forth. (Porges, 2001)
Posttraumatic stress disorder (PTSD) has been connected to low heart-rate variability (HRV), which can cause risk factors for hypertension, heart disease, and death. While hyperarousal and anxiety cause the underlying health risks and issues; smoking, alcohol dependence, obesity, and sleep disturbance can be contributing to the lower HRV. Within a study, HRV was assessed amongst young adults with and without PTSD to determine whether autonomic dysfunction in PTSD individuals is connected to the higher rates of these behavior health risks. Low HRV can cause issues among the immune system such as diabetes, osteoporosis, arthritis, Alzheimer's disease, some cancers, heart disease, heart attack, increase blood pressure. (Dennis, Watkins, Calhoun, Oddone, Sherwood, Dennis, Rissling, & Beckham, 2014) Along with the autonomic dysregulation of PTSD and the reduce HRV, these contributing factors could be making it worse. Individuals with PTSD are likely to smoke heavily, abuse alcohol, be overweight, and suffer from sleep disturbance. (Dennis, et al., 2014) HRV is negatively associated with PTSD and PTSD is connected to the behavioral health risks such as smoking, alcohol dependence, obesity, and poor sleep which supports the second hypothesis. (Dennis, et. al., 2014)
Benefits from psychiatric and psychological interventions in PTSD may help these health behaviors and improve the symptoms of PTSD and increase HRV. A decrease in these poor behavioral health factors could help increase HRV and restore health. (Dennis, et. al., 2014)
Trauma-informed therapy such as utilizing EMDR could help with understanding why the survivor struggles with overindulgence of substances and lack of sleep. EMDR has helped clients who have struggled with PTSD and nightmares. Many clients utilize hypnosis to quit smoking as well. Trauma seems to be the root of individuals with addiction issues. Combining educational and empowering classes and groups, helps one to work through the steps and helps them understand the connections to their addictions and trauma. There are wonderful exercise and eating programs that could help one to lose weight. Yoga practices, including meditation, relaxation, yoga postures, breathing, and integrated practices, appear to improve autonomic regulation and enhance vagal dominance. (Tyagi & Cohen, 2016)
Chronic Pain
In a normal response to fear or stress, the body gets prepared for flight and fight by mobilizing energy. Chronic stress can increase issues within the muscles and energy usage such as myopathy, a disease of the muscle in which the muscle fibers do not function properly, resulting in muscular weakness. It can cause inflammation and chronic pain. (Sapolski, 2017) Currently, the most common treatment to treat chronic pain is with medication such as opioid-based medications, anti-inflammatory drugs, muscle relaxers, and SSRIs. However, there are programs that include nonpharmacological treatments such as mindfulness, exercise, somatic therapies, and hypnosis. The most effective results are seen in these nonpharmacological treatments, but they are not available to all clients. (Marie & Talebkhah, 2018)
The goal of mindfulness in the treatment of chronic pain is to “create a quality of openness and experiential acceptance of pain, rather than rejecting or avoiding the pain”. ( Marie & Talebkhah, 2018, p. 2) Mindfulness is a great non-invasive approach. However, many clients who experience chronic pain, may not feel that inner reflection will be helpful, possible, or preferred over medications. However, according to Marie and Talebkhah’s (2018) studies, the evidence of mindfulness can be an effective treatment for chronic pain.
Mindfulness helps one to notice their internal and external experiences by observing what is going on without judgment or reactivity and being able to label it or describe what the internal experience is whether that is an emotion, thought, image, or pain. If one can be aware of themselves and their internal experiences, then one can release distortion and judgments of oneself and others which is considered as self-regulation. As someone utilizes mindfulness certain neurocognitive mechanisms begin to strengthen and integrate to help with the self-processing and reduce judgment. These mechanisms include intention and motivation, attention and emotion regulation, extinction, and re-consolidation, prosocial, non-attachment, and de-centering. (Vago & Silbersweig, 2012)
Mindfulness is known to help modulate the neural brain processes before and during painful stimuli. Meditators in a 6-week mindfulness-based stress reduction program reported less pain from painful stimulus while meditating, increasing activity in two areas of the brain connected to attentional processing. Meditators also had less activity in the amygdala, which is associated with pain anticipation. Mindfulness suggests that openness of oneself to an experience of pain (attentional processing) rather than avoidance (anticipation) may reduce the mind's tendency toward anxiety, which can increase the pain. (Marie & Talebkhah, 2018)
Digestion
The chronic stress and suppression of digestion can lead to issues such as ulcers, impairment in repairing stomach ulcers, or increase fat deposition. In the early 1900s, Hans Selye discovered ulcers in his studies with rats. (Rosch, 2010) Over time studies have shown that due to stress, the immune system goes down, and certain people can produce a bacterial disorder that can create ulcers (Heminway & Klagsbrun, 2008).
Corticotropin Releasing Factor (CRF) is a hormone that influences gastric changes in the body due to stress. CRF is released in the hypothalamus and the locus coeruleus of the brain. (Mertz, n.d.) These two primary brain regions, hypothalamus, and locus coeruleus both stimulate one another activating a stress reaction. Signals are sent to the limbic system to react to the stress response. CRF released activates the hypothalamic-pituitary-adrenal axis (HPA axis) involved in the stress response. Release of the CRF by the hypothalamus activates the pituitary gland which releases an adreno-corticotropic hormone (ACTH) to stimulate adrenal gland secretion of the stress hormone cortisol. Cortisol creates fluid and salt retention and impairs inflammation. If the HPA system is activated too many times stress disorders can occur. (Mertz, n.d.)
CRF stimulates the gut directly. It may be that the sensitizing effects of stress on the gut are partly due to the stress hormone CRF. Stress can cause issues in the colonic contractions, reduce gastric motility, and increase intestinal sensitivity. (Mertz, n.d.) Heartburn symptoms can occur as well. According to Mertz (n.d.), our gastrointestinal reactions are very similar to animals. The upper gut slows down digestion and may promote vomiting and reduction of appetite. The lower gut begins to speed up digestion, increasing stool output quickly. IBS patients may also have a greater sensitivity to the stress hormone CRF. Therefore, are more likely to experience more severe stomach issues when stressed. (Mertz, n.d.)
The gut microbiota is a key regulator and communicator of the gut-brain axis. The gut houses microbes, mostly bacteria, but also archaea, yeasts, parasites, viruses, and protozoa. (Foster et al., 2017) There are various processes through which the gut microbiota can signal to the brain. These include activation of the vagal nerve, gut hormone signaling, the immune system, metabolism, and microbial metabolites. Through these routes of communication, the microbiota-gut-brain axis controls key physiological processes that are all involved in stress responses. (Foster et al., 2017) Dysregulations of the gut microbiota consequently lead to changes in all these central processes and possibly creates stress-related disorders, such as anxiety, depression, and IBS. (Foster et al., 2017)
Diet is one of the most important factors of the microbiota-gut-brain axis and can reduce stress-related behavior. The theory of psychobiotics is being developed to help the microbiota and bring beneficial mental health outcomes. Psychobiotics are bacteria with positive effects on mental health are a specific subtype of probiotics and prebiotics, that promote the growth of beneficial bacteria. (Foster et al., 2017) Bifidobacterium can have a positive effect on the brain and behavior, enhance the cognitive process, and emotional learning. Bifidobacterium is a bacterium with positive anti-stress and pro-cognitive effects. Ingestion of psychobiotics was able to lessen the increase in cortisol production and anxiety responses. Stress was reduced by psychobiotic consumption. (Foster et al., 2017)
Hormones
Chronic suppression of growth hormone can cause issues with dwarfism, increased risk of diabetes, high blood pressure, obesity, and osteoporosis as adults. This is seen in survivors of childhood trauma and neglect. (Sapolski, 2017) Within the neuroendocrinological studies (Sherin & Nemoroff, 2011), it showed that abnormalities in catecholamines and cortisol levels were found in PTSD individuals. There are studies that show many changes in other hormonal and neuroregulatory factors. Low levels of cortisol levels were found in PTSD. (Pitman, et al., 2012) Endocrine factors that are within PTSD include abnormal regulation of cortisol and thyroid hormones. (Sherin & Nemeroff, 2011)
“The HPA axis is the body's major response system for stress and the hypothalamus secretes CRF which binds to receptors on pituitary cells which produce and release ACTH which is transported to the adrenal gland were adrenal hormones such as cortisol are produced and released. The release of cortisol activates sympathetic nervous pathways and generates negative feedback to both The hypothalamus and the anterior pituitary. This negative feedback system appears to be compromised in patients with PTSD.” (Sherin & Nemeroff, 2011, p. 4) The HPT (hypothalamic–pituitary–thyroid axis) access is involved in regulating and controlling the blood levels of thyroid hormones. The authors suggest that the elevated thyroid, HPT axis may relate to personal anxiety. (Sherin & Nemeroff, 2011)
Also, chronic suppression of reproduction can cause irregular or loss of cycles among women, the inability to reproduce, and low libido. Men struggle with decreased testosterone and erectile dysfunction and low libido. Women more frequently suffer from PTSD than men for reasons that are not clear. It may be because they are subject to different types of trauma. Studies suggest that females generally exhibit greater magnitude and duration of HPA axis responses to stress than males. Sex differences in neuroendocrine stress responses have been attributed to the direct effects of estrogen circulating neurons. Progesterone has been implicated in modulating the symptoms as well. (Sherin & Nemeroff, 2011)
The Immune System
When the immune system is enhanced chronically, it can increase the risk of infectious diseases such as the common cold or flu. Having a well-functioning immune system is central to good health. (Kiecolt-Glaser et al., 2002) Chronic stress can cause issues with the immune system affecting one to get sick easier and having a harder time fighting off illness such as HIV. There are reports that chronic stress can cause or make autoimmune issues worse, where the cells begin to attack one another. (Kiecolt-Glaser et al., 2002)
Psychoneuroimmunology is described as the interaction between psychological factors, the nervous system, and the neuroendocrine system. Between the central nervous system and the neuroendocrine system, they both share hormones, neurotransmitters, and cytokines to communicate with one another. (Thibodeaux & Rossano, 2018) Mostly, psychological factors, such as stress and emotions, influence the brain's immune relationship - either acute stressors enhance immunity, while chronic stress suppresses the immune system, and triggers inflammation. (Thibodeaux & Rossano, 2018)
With a meditative practice, one can reduce their stress and see positive effects that undo physiological reactions that lead to inflammation and reduction of immune function. Within several studies, meditation has proven to increases white blood cells to help target and kill stressed or abnormal cells, preventing tumors and viral infections. It also increases antibody production which helps to attack “viruses, toxins, and bacteria, along with regulating balance through wound healing, rejections of transplants and activation of T-cells”. (Thibodeaux & Rossano, 2018, p. 6) This has been seen in individuals that practice yoga, meditation, and breathwork. (Thibodeaux & Rossano, 2018)
Meditation has also been found to positively influence telomerase activity in immune cells. This DNA consists of caps, called telomeres, that offer protection from cellular deterioration and senescence, which happens when the telomere is shortened. Telomerases regulate the telomere length. Meditation among diet and living an active healthy lifestyle, are associated with longer telomeres and an increase in telomerase activity. (Thibodeaux & Rossano, 2018)
Meditation also keeps CD8+ T-cells stable during stressful times. CD8+ T-cells are white blood cells responsible for removing damaged and infected cells, preventing the spread of viruses and cancers. Meditation can also increase the antibody and T-cells to help slow down the progression of a virus, such as HIV. (Thibodeaux & Rossano, 2018)
Some other interventions that could help are hypnosis, relaxation, exercise, classical conditioning, self-disclosure, exposure to a phobic stressor to enhance perceived coping self-efficacy, and cognitive therapy therapies. (Kiecolt-Glaser et al., 2002) These tend to work well with HIV and Melanoma patients. An intensive group intervention reports that it was a positive consequence for mood, immune function, and survival. (Kiecolt-Glaser et al., 2002)
The Brain
Chronic stress and enhancement of cognition and mood can lead to disconnection of neuronal networks, inhibition of the birth of new neurons, and endangerment of neurons in the hippocampus can lead to learning issues and memory loss. Instead, anxiety is increased and the amygdaloid expands. The amygdala teaches one to be afraid and to know fear. While stress atrophies away at the neurons in the hippocampus (learning and memory), stress is making neurons in the amygdala work better than usual causing more fear and stress responsiveness. This can lead to the depletion of dopamine, inability to feel pleasure, and major depression. This is commonly seen among PTSD, combat trauma, sexual abuse survivors, and major depression. (Sapolski, 2017)
Pitman’s, et al. (2012) article, covers structural neuroimaging studies and shows how the most repeated structural abnormality found in PTSD is a lower volume of the hippocampus and of the PFC. PFC is another structure that is damaged by chronic stress.
The functional neuroimaging studies showed altered activity in the amygdala, PFC, dACC, and the hippocampus and the insular cortex in PTSD individuals. (Pitman, et al., 2012) The amygdala is a key structure for both the recognition of dangerous stimuli and the coordination of the fear response. It detects threats, fear learning, fear expression, and heightened emotional memories. These studies showed exaggerated amygdala activation in response to stimuli. PTSD individuals who have great amygdala activation experience the learning of conditioned fear. The PFC also shows a decrease in activation. Activation of these events’ negativity impacts severe symptoms of PTSD. The dorsal anterior cingulate cortex (dACC) serves as the response selection, error detection, pain perceptions, and fear learning and expression. Activation in the dACC is increased in PTSD. Hippocampus is involved in the encoding and recognition of memories. Failure to recall extinction learning is connected to lower hippocampus activation. The insular cortex is involved in monitoring internal bodily states. Those who show great activation in this area may reflect increase identification of bodily arousal during the stimuli. Increased activation appears in PTSD symptoms. (Pitman, et al., 2012)
A decrease in PFC activity was associated to increased amygdala activity. The PFC fails to inhibit the amygdala, leading to a bias towards the threat, increase fear responses, impaired extinction of traumatic memories, and its retention and deficits in emotional regulation. dACC seems to promote fear expression. (Pitman, et al., 2012)
Abnormal functions in the hippocampus may account for some of the cognitive symptoms of PTSD such as memory deficiency. The impaired hippocampus may create the generalization of fear conditioning and previous traumatic exposure impair the ability to discriminate between safe and unsafe stimuli. The exaggerated responses within PTSD limit capacity for the discerning threat due to hippocampus and amygdala dysfunction which can promote paranoia, hypervigilance, behavior activation, exaggerated stress responses and furthering activity of fear associations. Disrupted prefrontal cortex function may then serve to facilitate PTSD pathology further because of deficit suppression of stress response fear association and extinction. (Sherin & Nemeroff, 2011)
Conclusion
Chronic psychosocial stress can increase issues within the muscles and energy usage such as myopathy. The increase in cardiovascular tone can increase hypertension and heart disease. The chronic suppression of digestion can lead to issues such as ulcers, impairment in repairing stomach ulcers, or increase fat deposition. Chronic suppression of growth hormone can cause issues with dwarfism, increased risk of diabetes, high blood pressure, obesity, and osteoporosis as adults. This is seen in survivors of childhood trauma and neglect. The chronic suppression of reproduction can cause irregular or loss of cycles among women, inability to reproduce, and low libido. Men struggle with decreased testosterone and erectile dysfunction and low libido. When the immune system is enhanced chronically, it can increase the risk of infectious diseases such as the common cold or flu. Chronic stress and enhancement of cognition and mood can lead to disconnection of neuronal networks, inhibition of the birth of new neurons, and endangerment of neurons in the hippocampus can lead to learning issues and memory loss. (Sapolski, 2017)
There are ways that can help one to regulate their stress response and learn how to heal from PTSD utilizing several modalities that were mentioned such as therapies that help to “decrease the amygdala activation and to increase PFC activation”. (Friedman, 2015, p. 12) Along with modalities that can help stimulate the human's vagus nerve in order to energize the parasympathetic nervous system which then relaxes the body, turns off the stress response, halting the release of cortisol and adrenaline, and so forth. (Porges, 2001) These include psychiatric and psychotherapy interventions include EMDR, EFT, hypnosis, yoga, breathing, meditation, healthy diet, probiotics, physical movement, cognitive-behavioral therapies, outlets for frustration, sense of predictability, and of control, a perception of life-improving, and social supports.
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