How can stress affect health? - Chapter 11

What are the concepts of stress?

Everyone experiences stress sometimes, and we all know people with a stressful life due to their job, busy family life or due to a chronic illness or psychological problems. In science, stress is viewed in a different way. It is seen as as a stimulus, the psychological transaction between the stimulus and the emotional and cognitive expressions and as a biological response.

Different approaches to stress

When we think of stress as a stimulus, it is about events that people think they might not be able to cope with, or that they think will be very tough like moving, divorce but also positive things, such as the birth of a child. The way someone approaches such situations and the control they think to have is very important.

Research into what people think is the most stressful event, resulted in a list of life events. This is a list of events that can be both positive and negative, but are a stressful experience for everyone. At the top of this list is the loss of a life partner, followed by divorce, the death of a family member and personal injury or serious illnesses. The higher the score of the life event, the greater the risk to health. The weak points of this commonly used and globally known list is that the death of a child is not on the table and that events such as ending up in prison do not occur because they are not experienced by most people.

In addition to important and often rare life events, research has demonstrated the stressful nature of daily hassles. Hassles are irritating, frustrating, stressful events that are characteristic of daily life.

A striking difference between men and women is that women are psychologically influenced by both the positive and the negative daily events, while men suffer only from the negative things.

The transactional model of stress

Lazarus and Folkman presented the transactional model of stress in the mid-1980s. Prior to the development of this model, research had been done into the influence of psychological processes on stress. A group of participants was divided into four conditions before they were shown horrible film material from operations on genitals, among other things. The four conditions determined what accompanying information the participants received with the film images:

1. An informative description of the images from a cultural perspective.
2. Information that says that people on the film undergo the operations voluntarily and that they themselves are very excited about it.
3. Information that indicates how much pain people suffer on the images and how traumatic it can be.
4. No accompanying information at all.

The results make it clear that it matters what information someone gets with the images. The people in the first two conditions had significantly less stress than group three. According to Lazarus, stress is the result of someone's character and approach, the internal or external event and the internal or external resources that someone has to deal with.

When people get into a new or challenging situation a process of approach stars, which can be primary or secondary. With a primary approach, someone considers the quality and nature of the event. There are three types of stressors: harmful, threatening and challenging stressors. Depending on the type of stressor, a person considers whether the event is relevant to that person, whether it is positive or negative, whether something should be done about it and whether it is a threat. This can lead to emotions that can also have physical consequences.

Secondary approach means that someone looks at how his possible sources can be used to deal with the stressor. Someone can ask themselve how to deal with the situation.

If someone cannot use limited (auxiliary) sources, it results in stress. Challenges with uncertain internal sources (not sure if you can handle the challenge) also result in stress. If someone thinks they can handle the event, this will not lead to stress, even if the challenge is big or the event is fierce.

The model was later added with the degree of relevance (motivational relevance) and the degree of congruence (motivational congruence). These two new developments belong to the primary appraisal. If in a situation the relevance is high but the congruence with someone's goal is low, then stress is likely to result. Lazarus also added the ego involvement, which indicated what kind of response the individual will give to each type of threat.

Smith made four types of approach to the two types of approach (in the secondary appraisal):

1. Internal or external statement: where do you place the responsibility for what happens. When you see someone else as responsible, this is accompanied by anger and when you see yourself as responsible you can feel guilty.
2. Problem-oriented coping: can the situation be changed with practical, problem-oriented options? If this is not the case, feelings of fear can arise.
3. Emotion-focused coping: to what extent does someone think they can handle the situation emotionally? If someone thinks that they cannot handle the situation emotionally, this leads to fear and sadness.
4. Expectations for the future: to what extent someone thinks the situation will change in the future. If someone thinks this will not happen, it can cause sadness.

Criticism of the work of Lazarus

The approach theory of Lazarus corresponds to different biological and psychological models and takes into account all the 'ingredients' of a good model. However, there are few minor comments. For example, little is known about the interaction between primary and secondary approaches and between the alleged demand of the new situation and the alleged coping. The question is also whether primary and secondary approaches are necessary to prevent stress.

Factors that influence the approach:

• How quickly something will happen (compare your feeling about an exam next month with an exam tomorrow).
• If something happens unexpectedly or expected.
• An event that is unpredictable in nature. 
• Events that are ambiguous with regard to the personal role or task or potential risk.
• The (un) desirability of the event.
• The alleged control over the event.
• The amount of change that the event will cause.

What types of stress are there?

Stress and resource loss

The conservation of resources model of Hobfoll says that people try to preserve their valuable resources, such as objects, properties, energy, money, self-confidence, etc. Stress will arise when conservation is threatened or when the resources are actually lost. This model is similar to the model of socio-economic deprivation, in which unemployment and poverty are associated with illness. In the conservation model, however, it is not made very clear which constructs have what influence and how long a loss must last. For example, to have an impact on someone's health. Hobfoll stated that especially acute changes cause stress. An example of an acute event is a natural disaster, such as a hurricane in which someone's house is lost.

Acute stress

Natural disasters such as tsunamis and technological catastrophes like Chernobyl (1986) happen so unexpectedly that people hardly have time to prepare for the consequences. The environmental stress theory sees stress as a combination of psychological and physiological responses to the demands of the new environment (a village destroyed by a hurricane).

Examples of expected reactions are: panic, anxiety, phobic anxiety, guilt, isolation, withdrawal, anger, frustration, personal or relationship problems, disorientation, detachment of loved ones, eating problems, sleeping problems, a diminished feeling.

How bad those reactions are depends on the loss. For some people the event keeps coming back in the form of dreams or flashbacks. In that case, someone is probably suffering from post-traumatic stress disorder (PTSD). Research shows that the loss is positively associated with long-term stress. Active coping influences the relationship between the two and reduces stress when it is a good way of coping.

Interventions work best when something is done about the loss (such as reconstruction after a hurricane) and the self-image of the victims. If they think they can handle what happened, it will reduce stress and negative outcomes.

Exam stress

Everyone knows that you can get very nervous about exams and you can even get stressed feelings. Unfortunately too much stress has a negative influence on our performance and memory. For example, you cannot understand questions while they are clearly formulated or just don't always get an answer, while it is on the tip of your tongue. The Yerkes-Dodson Act states that there is an optimum level of stress that benefits performance, but that too much or too little stress has a negative impact. For complex tasks, a lower degree of stress is better and for simple tasks, a bit more stress is often better. Stress also influences the behavior, for example smoking and eating behavior of people who have to take an exam.

Chronic stress

Stress in the workplace

Just like exam stress, work stress is something that most people will experience. Usually the stress will be short-lived, for example when a deadline has to be met, but sometimes the stress will be long-lasting and accompanied by sleeping and eating problems. This can ultimately result in burnout. Burn-out is described by Maslach as exhaustion, depersonalization and no longer reaching personal goals.

What makes some jobs so stressful is described by the environment fit theories and the goodness-of-fit theory of Lazarus. These theories state that stress occurs when there is no good combination of environmental and personal factors. When research on this topic was first conducted, the focus was mainly on environmental factors. An example of an early model is the Job demand control model (JDC) of work stress. This model describes the following characteristics that would lead to stress:

• Work requirements (is high if the work is always heavy and there are constant deadlines).
• Controllability.
• Predictability.
• Ambiguity.

You can question these characteristics with specific questions.

The combination of question and control would determine whether an employee experiences stress. Controllability was initially seen as a kind of buffer for experiencing stress with high work demands. However, studies using the JDC model showed that there was little evidence for the negative impact of work demands on employee well-being. Now it seems that work requirements and controllability have an independent and direct influence on whether or not to experience stress. If a job demands too little from an employee, this can also cause stress, because someone gets bored quickly at work and parts of the day have nothing to do. All these things are also not beneficial for the employer, because they often result in illness, absenteeism, accidents and reduced productivity.

Research into demand-control-support models shows that more attention needs to be paid to the status and gender of employees before interventions in the stress experienced. For many female staff it is useful to focus interventions on self-confidence and for people in high positions, more support from the workplace itself is often needed.

What is meant by stress as a physiological response?

An event must be approached or assessed in a certain way. This requires the central nervous system (CNS). Sensory information and approach together ensure that automatic and endocrine responses take place. The latter two provide feedback to the cortex and the limbic system, which in turn are related to the hypothalamus and the brainstem.

In 1932, Cannon discussed the role of adrenaline and noradrenaline, which end up as hormones in the sympathetic nervous system and contribute to the fight or flight response. Adrenaline ensures that someone has a lot of energy and can run away quickly or respond quickly in a fight. For this reason, the system is adaptive, but it is also harmful because it disrupts emotional and physical functions. When a stress reaction lasts for a long time, that disrupted effect can even result in illness. Another researcher, named Selye, accidentally came up with a number of findings during the study of sex hormones in animals. He found, for example, that injecting hormones, which was not a pleasant procedure for the animals, resulted in enlarged adrenal glands, a reduced thymus gland and tumors around the genitals of the animals. Selye did another 40 years of research into this phenomenon and used stimuli as injections, hot and cold stimuli and exercise and came to the conclusion that there are universal and non-specific responses to stress. It becomes Selye's model called general adaptation syndrome (GAS). Stress reactions appeared to be an attempt to maintain inner balance and homeostasis.

Selye proposed a three-phase process:

1. Alarm response: the sensation of the stressor that causes the immune system to stop and raise blood pressure and heart rate
2. Resistance phase: the body tries to adjust to the stressor. The excitement has dropped slightly but is still higher than normal. Someone cannot stay in this phase indefinitely without becoming ill.
3. Exhaustion phase: exhaustion takes place if the resistance phase lasts too long. Stocks in the body become exhausted, so that someone has no energy left. It is no longer possible to resist the stress and it is likely that someone develops heart problems, asthma or other stress-related diseases.

The work of Cannon and Selye resulted in a lot of research into the physiology of stress. This resulted in Cannon's non-specificity of stress response responses being rejected. Different types of stress can be associated with different types of reactions. For example, more adrenaline is found in the blood when someone has mental stress and more noradrenaline when someone experiences physical stress. Research has shown that the typical stress response is not only caused by activation of the anterior-pituitary-adrenal cortex, but also by increased activity of the sympathetic branch of the autonomic nervous system. The ANS can be divided into two connected systems: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS).The SNS is involved in excitement and expansion of energy, while the PNS is involved in reducing excitement and recovery of energy. Activation of the sympathetic adrenomedullary system (SAM) leads to the release of adrenaline and noradrenaline from the medulla. This allows a person to respond immediately to a stressor, such as fighting or fleeing. The second system that is turned on is the hypothalamic-pituitary-adrenocortical system, which allows organs to change their usual function to effect a longer-term adaptive response to internal and external stressors. SAM and HPA thus provide total coverage for the stress response, one via adrenaline for the acute response and the other via cortisol for longer-lasting reactions, while the PNS is involved in reducing excitement and restoring energy. 

Stress and immune function dysregulation

Stress can cause changes in the immune system and the endocrine system that in turn lead to the development of disease. This mainly happens when the stress is chronic. Immune cells are white blood cells: lymphocytes and phagocytes. The phagocytes are attracted to infected sites, and they then destroy abnormal cells or antigens. Phagocytes provide the non-specific immunity. Lymphocytes are for specific immunity and involve T cells made in the thymus (cell-mediated) and B cells (humoral immunity). The HPA system causes the release of hormones such as cortisol, and these stimulate the immune system. Glucocorticoids inhibit the production of B and T cells, thereby reducing immunity.

The immune function decreases with age. This allows the elderly to respond more strongly to infections. Stress can also change physiological responses. The reactivity hypothesis describes how genetic or environmental factors combine to influence a person's vulnerability to a physiological response after stress and negative emotions, which can be harmful to health.

What is the link between stress and illness?

The route described above is the direct route from stress to disease. Stress also has an indirect influence on health:

• People respond to stress by smoking, drinking and eating healthier. This falls under the poor coping strategies.
• People who experience a lot of stress are more likely to seek help in health care than people who experience less stress. These people initially seek help for the symptoms (anxiety, fatigue, shakiness) of the stress.

Stress and the common cold

In a Cohen study, participants were divided into a condition in which they had to breathe in the rhinovirus (which causes a cold) and a condition in which they thought this was happening, but the participants actually had to breathe in saline drops. People who had reported chronic, negative events had more symptoms of infection in both conditions than people who had not experienced any negative things. This research points to the relationship between long-term stress and a cold.

Stress and coronary heart disease (CHD)

CHD is a disease of the cardiovascular system that develops gradually. It can arise from a hereditary sensitivity or a person's way of life. The direct cause of CHD is the narrowing of blood vessels, making blood flow to the heart increasingly limited. If blood is pumped faster from the heart during stress, this can damage the walls of the blood vessels. Hypertension also contributes to the risk of CHD.

Under the influence of stress, the sympathetic nervous system ensures that fatty acids enter the bloodstream. These fatty acids are converted into cholesterol by the liver if they are not used as energy. Cholesterol in turn forms a layer of fat on the walls of the blood vessels. Especially in places where the blood vessels were already damaged.

The release of catecholamines during stress also contributes to the fatty layers on the blood vessel walls.

Those layers on the walls can also become a plug and flow through the blood vessel, until they reach somewhere that they no longer fit through, so that the blood vessel is completely sealed off. Blocking a vessel to the heart or brain in this way leads to a heart attack or stroke.

In 1994, Rosch made a distinction between causal factors and factors that contribute to this. According to him, the direct ('true cause') is always biomedical. Smoking and stress can contribute to that biomedical cause, but smoking can never be the real cause of a heart attack.

Stress and cancer

Like heart disease, cancer is a disease that starts slowly due to the mutation of cells and the development of undetectable neoplasm, which can develop into tumors that spread. Different forms of cancer vary enormously in size, growth, spread and prognosis because they differ in sensitivity to changes in the immune system and neuroendocrine systems.

Stress can influence the course of cancer, because it delays the recovery of tumor cells. The studies on the influence of stress on (breast) cancer still contradict each other. Some studies show that stress is related to the recurrence of cancer. Ultimately you can state that there are now enough research results to assume that coping style (helplessness or hopelessness) and mood can influence the outcome and prognosis.

Stress and bowel diseases

On this subject, stress is seen primarily as a factor that can aggravate the condition, and not as much as a factor that causes the disease.

Irritable bowel syndrome is a disease of the colon that causes abdominal pain and diarrhea or constipation, while this is not caused by organic disease.

Another disorder is inflammatory bowel disease (inflammatory bowel disease, IBD), which is to be divided into Crohn's disease and ulcerative colitis. The diseases are characterized by pain and diarrhea.

In studies of these diseases, people are found where these diseases are influenced by stress, but also people where these diseases do not seem to be affected by stress. For people who do respond to stress, the symptoms can get two to four times worse due to stress. However, looking at the influence of stress on health and disease in general, this already explains a large part of the differences in IBS symptoms in these people.

Stress and HIV or AIDS

AIDS is now the leading cause of death in Africa and the HIV virus is also making many victims in other parts of the world. HIV is a so-called retrovirus, which means that it contains RNA and works slowly. It can take years for an HIV-infected person to develop AIDS.

Apart from the fact that AIDS is life threatening, it is also very psychologically stressful, due to the taboo on and the associations with the disease. AIDS (and HIV) also makes it difficult to have a sexual relationship. There are some indications that indicate that stress plays a role in susceptibility to the HIV virus and it is very likely that stress plays a role in the infection when someone has the virus.