Biology 202
2002 Third Paper
On Serendip

Progress has always been an essential component in modern society. At times it is equivalent to success, learning, and overall growth. In the field of science, progress is measured by comparisons to what was known before, what is known now, and what can be known in the future. Therefore, one could say that much progress was made in the field of science in terms of understanding the functions of the human brain and some of its behavior. It seems that as each new day passes, something new is discovered about the brain, whether it be a new mental or physiological brain condition, or merely a link and clue to one of the vast number of questions the world has considering the human brain and behavior. These discoveries and answers are becoming more and more important and imperative due to the fact that the overall population seems to becoming more and more emotionally fragile and more subject to several cerebral ills such as depression, anxiety, hysteria, and clinical insanity.

A good question to ask is whether or not the overall population seems to be suffering more mental and cerebral ills, or that it is merely a result of more cases being reported and more statistics calculated. But if it is true that the number of people suffering from conditions or types of behavior which hinder their ability to go on with their everyday lives, what is the cause? And when we find the cause, what is the cure? Or how will society as a whole handle it?

A possible theory is to look at the correlation between the rate of growth and process in modern society and the stress level of the average individual. Another question to ask is what exactly is the role stress plays in an individual's overall health, both physically and mentally? Could it be a key factor in this sudden uprising of mental ailments and the loss of many people's emotional and mental balance and stability?

There are numerous studies linking stress with a multitude of health problems, many with a neurobiological connection. One of the biggest things stress takes it's toll upon is the immune system. The impact of stress on physical health is clearly evident, as it has been reported that ninety percent of all doctor's visits are due to stress-related ailments and stress-related disorders. Chronic acute stress leads to a shift in the balance of one's biochemistry, one symptom being suppressed serotonin.(1) It has become common knowledge that most clinically diagnosed cases of depression are treated with serotonin drugs, believing that the cause of the depression is a lack of that cerebral hormone. Depression appears to be one of the conditions that is on the rise and is given specific attention by the scientific and psychological community.

There is a specific way in which the body responds to stress. Doctor's call this reaction General Adaptation Syndrome (GAS). The process itself has the potential to enter several stages, depending on how the individual responds and reacts to certain levels of stress. When the stress is first triggered, the brain initiates 1400 different responses, including the dumping of a variety of chemicals into the blood stream. Usually it is adrenaline or some kind of chemical, which gives the body a boost of energy to temporarily give it the ability to withstand whatever is happening at the moment. This is the first stage of GAS, also known as the "fight or flight response". The body will go back to normal once the source of the stress is removed. However, if the stress source is not removed the body will go onto stage two of GAS, called "resistance or adaptation". The body goes into a longer lasting protection mode, including the raising of blood sugar levels and blood pressure to provide sustained energy. The adrenal cortex of the brain also gets involved by producing hormones called corticosteroids. If the body uses this defense mechanism for too long, it can lead to disease and a weakening of the immune system. The third and final stage is exhaustion. The body has run out of its reserves of energy and immunity. It is at this stage where the mental, physical, and emotional resources suffer greatly. Everything drops, blood sugar levels, adrenals get depleted, all systems shut down and the body collapses. Usually this leads to a decreased stress tolerance for later on, progressive mental and physical exhaustion, and illness.

This chain of reaction cycle is a cleverly designed mechanism for survival for humans, but continual stress early in life can disrupt it. For some, even when the source of stress is removed the process will continue. The brain, specifically the hypothalamus, will continue signaling the adrenals to produce the cortisol hormones. This exhausts the stress mechanism and leads to fatigue and depression. These continually high levels of cortisol has been shown to suppress the immune system, adding evidence to the theory that stress and depression have a negative effect on the immune system.(2) An activity or reaction, which involves some brain activity, especially a strain on brain activity has the potential to damage other areas. The suppressed serotonin and overload of cortisol are a clear and rational explanation for the possibility of depression to arise in the individual suffering from intense, chronic stress.

There are physiological side effects specifically on the brain itself due to stress. A study at Stanford shows that a prolonged flow of stress hormones can actually cause shrinking in certain brain areas, particularly in the hippocampus, which plays a major role in memory. Therefore it is no unusual for people with prolonged stress to experience forgetfulness and have difficulty learning.(3) Stress-induced structural changes in brain regions such as the hippocampus, due to an overflow of stress hormones such as cortisol, have clinical ramifications for disorders such as depression, post-traumatic stress disorder and individual differences in the aging process. Abnormalities of the stress system activation have been shown in behavioral syndromes such as melancholic depression. The stress response is central to resistance to behavioral syndromes,(4) therefore it's easy to see how constant exposure to stress and the wearing down of the system itself can make someone clearly more susceptible to developing symptoms of, and even becoming completely enveloped in, clinical depression.

The constructs of our society make it difficult for most to handle their stress in the way the body naturally does. The innate impulse is to either run from the situation which is causing the stress or fight it. Take for example a situation where one individual, a boss, is yelling at one of his employees. The employee goes through the natural, GAS response and probably either wishes to run away or hit the yelling boss with everything he has. Of course the employee does neither of these or risk losing his job. Therefore, it is the body itself that has to deal with it, using and burning up a lot of energy because all in all there is nothing that can be done in response to the reaction from the stress. The fact that people in today's society cannot, without putting themselves socially at risk, do or react in the way that nature intended leads to a more damaging effect from stress. Evidently the lack of damage from the outside is balanced out by the potential damage on the inside.

A contributing factor to the ever-growing plague of stress is from mother to child. New research shows that prenatal stress could significantly influence development of the brain and organization of behavior in fetus. Because stress affects many of the body's systems— nervous, cardiovascular, endocrine and immune— there is good reason to believe that severe emotional stress could cause defects in the fetus, especially during the first trimester of pregnancy when development occurs at the fastest rate. In women who are exposed to severe stress and anxiety, this effect is caused by reduced blood flow through the arteries that feed the uterus. Usually, the cranial nerve crest, a structure of cells that is thought to contribute to the development of the head and face in a fetus, gets affected. According to Dr Vivette Glover, research head of a study linking obstetrics, pediatrics, psychology and psychiatry, experiment on animals shows that maternal, fetal, or neonatal experience can set the stress responses of the developing offspring for life. If true, in human beings this could predispose children to have behavioral problems, such as hyperactivity, or cause them to suffer from depression in later life.(5)

A hypothesis that could easily be made is that the way our society has progressed leads to lives filled with complexity and incredibly high levels of stress. Since humans are not able to deal and process the reactions of stress in the nature that was originally intended, and the fact that many of the sources of stress simply do not go away (for example: work, family, relationships, the environment), stress has in a way become an epidemic of it's own. The physiological and psychological effects are knocking people off their delicate balance and raising the levels of anxiety and depression amongst the population. Perhaps evolution will take hold and those with brains and systems more well adapt to handling this relatively new level of stress will flourish, making our society stronger. Or it could have a reverse effect, making society weaker in the process. Hopefully stress and it's harmful effects will be brought to attention more by the scientific community and as a whole society will do something about it or risk suffering from the potential set backs.

1)Physiological Effects of Stress
2)Holistic-online
3)http://www.brainsource.com/stress_&_health.htm
4)Neurobiology of Stress
4)http://www.lifepositive.com/Mind/psychology/stress/symptoms-of-anxiety.asp



| Forums | Serendip Home |