Tuesday, September 2, 2014

What Does Stress Do and How Can You Mitigate the Effect?

James-Lange Theory of Emotions proposes that emotions are the brain’s interpretation of physiological responses to emotionally provocative stimuli . Darwin proposed that emotions played a significant role in the survival of the species and resulted from similar evolutionary processes as other behaviors and psychological functions did. For example: Emotion’s like fear invoke actions that either could attempt to overcome the source of fear through fight or run from the source through flight. In this way, emotions help us process and respond to danger cues which aids in our survival. However, prolonged stress exposure and the constant activation of the Fight or Flight responses are associated with negative affects as well. 

Fight or Flight Response is provided by activity from the sympathetic branch of the autonomic nervous system. Fight or Flight Response is responsible for this biological process that prepares us for action in emergencies including producing stress hormones epinephrine, norepinephrine, and cortisol. In anticipation of a sudden demand for energy needed to escape danger, a release of epinephrine induces glucose metabolism which in turn starts to metabolize nutrients stored within muscles to become accessible in order to provide energy. Norepinephrine is also released and increases blood flow to muscles by increasing the flow of blood from the heart (Carlson, 2009, p. 601).       

Norepinephrine is not just a stress hormone released in the body as it is also found secreted in the brain as a neurotransmitter (Carlson, 2009, p. 601). The amygdala is fundamental to emotional processes, especially those relating to fear. The amygdala is a structure located in the interior of temporal lobes (Argosy Online Universities Lecture, 2013). When exposed to stressors a stress response is activated in a pathway from the “central nucleus of the amygdala to the locus coeruleus”, provoking release of norepinephrine from the brain. It is within the nucleus of the brain stem that the norepinephrine-secreting neurons are located (Carlson, 2009, p. 602). Corticotropin-releasing hormone activates the secretion of ACTH by the anterior pituitary gland in the brain, where it in turns also contributes to some of the emotional responses typically seen in stressful situations (Carlson, 2009, p. 611).

Cortisol, also called glucocorticoids, is a steroid secreted by the adrenal cortex, especially during experiences of stress, and is vital to survival (Carlson, 2009, p. 602). Cortisol is vital in the metabolism of protein and carbohydrates (Carlson, 2009, p. 602). Glucocorticoids have a specific function of helping with the endogenous decomposition of protein and converting it to glucose. This makes fats available for “energy, increase blood flow, and stimulates behavioral responsiveness by affecting the brain” (Carlson, 2009, p. 602). Glucocorticoids also affect the ability of the gonads to sense luteinizing hormone (LH) causing less endogenous production of sex steroid hormones (Carlson, 2009, p. 602). Long-term exposure to stress induced glucocorticoids has been demonstrated to destroy neurons located in hippocampal formation which is largely associated with cognitive functions such as learning and memory (Carlson, 2009, p. 604). This cell death is caused by the decreases in the uptake of glucose and decreasing the reuptake of glutamate, causing extracellular glutamate which permits calcium to pass through NMDA receptors and kill neurons (Carlson, 2009, p. 604). While Glucocorticoids aid in vital functions prolonged exposure to stress induced Glucocorticoids is associated with damage to “muscle tissue, steroid diabetes, infertility, inhibition of growth, inhibition of the inflammatory responses and acts to suppress of the immune system” (Carlson, 2009).

Prolonged exposure to glucocorticoids works to suppress the immune system (Carlson, 2009, p. 610). Immune suppression from stress can put one at risk for upper respiratory infection and colds (Carlson, 2009, p. 610). Studies indicate that increases in the number of undesirable events and a decreases number of desirable events in ones life leads to medical illness through immune’s suppression of the immunoglobulin, IgA, in mucous membranes of the nose, mouth, throat, and lungs (Carlson, 2009, p. 610). Immunoglobulin, IgA, is the primary defense against infectious microorganisms that enter the nose or mouth and is affected by mood (Carlson, 2009, p. 610-611). This risk would naturally be increased if ones immune system was already suppressed either by medication, illness, or age.

A stimulus that causes us psychological distress causes the emotions and feelings associated through increases in stress hormones from activation of the “Fight or Flight Response” (Carlson, 2009).  The stress response produces an increase in epinephrine and cortisol which will assist in our escape, but escape from certain life events is not always possible. This leaves the person who is suffering from prolonged exposures to stress at risk for a variety of psychological symptoms, physical illnesses, and brain damage from stress hormone toxicity. Prolonged stress is also associated with increased blood pressure from the increases in stress hormones Norepinephrine and Epinephrine. Over time contributes to cardiovascular disease and variety of other illness like stress disorders. While prolonged over exposure to stress induced Cortisol or Glucocorticoids is associated with damage to “muscle tissue, steroid diabetes, infertility, inhibition of growth, inhibition of the inflammatory responses, and suppression of the immune system” (Carlson, 2009, p. 603). 


Prolonged exposure to stress can cause brain abnormalities, specifically in the hippocampus and amygdala formations, as seen in studies of patients with PTSD and Stress disorders (Carlson, 2009, p. 607). PTSD is a psychological disorder which results from exposure to a situation of extreme danger and stress and includes distressing symptoms like recurrent dreams or intrusive recollections of trauma that interfere with social activities and cause a feeling of hopelessness (Carlson, 2009, p. 606). The hippocampus play a vital part in contextual learning including participating in the recognition of the context in which a traumatic experiences occur and later helping one distinguish safe from dangerous context (Carlson, 2009, p. 607). One hypothesis suggests that after a person is attacked by something a traumatic trigger is created and stored with traumatic stimuli, however, because of the damage to the hippocampus the ability to distinguish actual traumatic stimuli from similar stimuli is impaired resulting in the activation of the amygdala and the trigger of an emotional response in the face of similar stimuli (Carlson, 2009, p. 607). The prefrontal cortex can exert an inhibitory effect on the amygdala and suppress emotional reactions including the loss of conditioned emotional responses like fear (Carlson, 2009, p. 607). Evidence suggest that actions from prefrontal cortex inhibiting the activity of the amygdala may be liable for emotional reactions and psychological symptoms such as difficulty falling or staying asleep, irritability, outbursts of anger, difficulty in concentrating, and heightened reactions to sudden noises or movements found in persons with PTSD (Carlson, 2009, p. 607-608).

             The above changes in physiological fight or flight response to stress and its affects on cognitive or emotional changes would be similar in most persons who were living under these same stressors, what would likely differ is the length of duration before the onset of symptoms that impair with function. If the same stressor were being experienced by a person of the opposite sex or someone much older or younger there might be some differences in how they react emotionally. For example: men may be less tearful and frightened and react with more anger and hostility, while an older or wiser person may feel unabashed and a younger person may be completely depressed and express with hyperactivity and impulsivity, instead of fear and tears. How someone reacts to a stressor is largely based on their ability and resources to deal with the problems, how much social support they have, their previous trauma experiences, personality, temperament, coping skill and lastly, how long the stressor persists.

The four most important behavioral strategies I would suggest one implement immediately to reduce the effects of stress on my body is care for themselves by making sure they get adequate sleep, sun, nutrition and exercise.

Getting proper nutrition is important because nutrients play a vital role in neurotransmitter metabolism. Vitamin deficiencies are often found in subjects with depression and being properly nourished supplies the body with minerals such as calcium, iron, magnesium, selenium, and zinc that aid in preventing depression, irritability, and mood swings (Masley, 2013). One of the most important things I can do to combat stress is work on making sure I have a stock of healthy ready to eat items handy.

Exercise has been shown to increase serotonin function, so exercising can help induce a positive mood (Young, 2007). Several studies have confirmed a relationship between serotonin and mood, indicating that less serotonin correlates with more negative moods (Young, 2007). Studies that have researched exercise and the relationship with mood concluded that exercise has an antidepressant and anxiolytic effects, plus increases brain serotonin function (Young, 2007).

Get more sunlight, which can help increase serotonin levels and improve mood.  A studied has demonstrated a “positive correlation between serotonin synthesis and the hours of sunlight received” that day; therefore increasing my sunlight can also help me fight feelings of depression (Young, 2007).

Why exactly the brain needs to sleep is perhaps poorly understood, but it is clear that decreases in sleep later results in poor cognitive function and psychological symptoms because sleep deprivation impairs cerebral functioning (Carlson, 2009, p. 310). As the brain activity utilities glycogen as fuel for neural activity it’s levels drop producing extracellular adenosine chemicals, which then accumulate prohibiting normal neural activity (Carlson, 2009). This chemical toxicity produces both the cognitive and emotional effects that are seen during sleep deprivation and process that occurs during sleep helps restock glycogen for tomorrow.

Poor sleep results in poor cognitive performance because it is during sleep, particularly during slow wave and REM state, that our brains restore cognitive function and process information (Carlson, 2009). Increases in mental activity, including dealing with stressors, would cause an increased need for slow wave sleep to facilitate consolidation of explicit memories (Carlson, 2009, p. 307). REM sleep is equally important and is believed to play a major role in the development and learning, particularly the consolidation of long-term memories and implicit memories (Carlson, 2009, p. 309). Decreased sleep also causes increases in highly reactive oxidizing agents called free radicals within the brain (Carlson, 2009, p. 307). During a process called oxidative stress, free radicals can bind with electrons from other molecules and damage the cells that they inhabit (Carlson, 2009, p. 307). The decreased metabolic rate during slow wave sleep allows for the restorative mechanisms to eliminate free radicals before damage occurs (Carlson, 2009, p. 307). Clearly, getting enough regular sleep will improve my cognitive function and emotional well being.

The most important skill one must demonstrate to implement these is time management.







References

Carlson, N. R. (2009). Physiology of Behavior, 10th Edition. Pearson Learning Solutions. VitalBook file.

Mills,H.  Reiss, N.  Dombeck, M. (2008). Cognitive Therapy Techniques for Stress Reduction.  MentalHelp.  Retrieved from http://www.mentalhelp.net/poc/view_doc.php?type=doc&id=15667&cn=117

Masley, J. (February, March 2005). The role of exercise, nutrition, and sleep in the battle against depression. Mental Health Matters. 2(5,6). Gratiot Medical Center: An Affiliate of MidMichigan Health. http://fhpcc.com/PDFs/RolesAgainstDepression.pdf


Young, S. M. (2007). How To Increase Serotonin in the Human Brain Without Drugs. Journal of Psychiatry Neurosci. 2007 November; 32(6): 394–399. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2077351/