Chapter 5: stress and physical and mental health

The field of health psychology is concerned with the effects of stress and other psychological factors in the development and maintenance of physical problems. Heath psychology is a subspecialty within behavioral medicine. A behavioral medicine approach to physical illness is concerned with psychological factors that may predispose an individual to medical problems.

These may include such factors as stressful life events, certain personality traits, particular coping styles, and lack of social support. Within behavioral medicine there is also a focus on the effects of stress on the body, including the immune, endocrine, gastrointestinal, and cardiovascular systems.

Exposure to extreme and traumatic stress may overwhelm the coping resources of otherwise apparently healthy people, leading to mental disorders such as posttruamatic stress disorder (PTSD).

This chapter discusses the role that stress plays in the development of physical and mental disorders. The mind and the body are powerfully connected and stress takes its toll on both.

1. What is Stress

When we experience or perceive challenges to our physical or emotional well-being that exceed our coping resources and abilities, the psychological condition that results is typically referred to as stress.

External demands are referred as stressors, to the effects they create within the organism as stress, and to efforts to deal with the stress as coping strategies.

Stress is fundamentally an interactive and dynamic construct because it reflects the interaction between the organism and the environment over time.

Both kinds of stress, negative or positive situations can tax a person's resources and coping skills, although bad stress (distress) typically has the potential to do more damage. Stress can also occur in more than one form-- not just as a simple catastrophe but also as a continuous force that exceeds the person's capability of managing it.

a. Stress and the DSM

The relationship between stress and psychopathology is considered so important that the role of stress is recognized in diagnostic formulations. The DSM-5 introduced a new diagnostic category called trauma-- and stressor related disorders.

Disorders in this category are adjustment disorder and acute stress disorder. These disorders involve patterns of psychological and behavioral disturbances that occur in response to identifiable stressors.

b. Factors Predisposing a Person to Stress

People perceive and interpret similar situations differently and also because, objectively, no two people are faced with exactly the same pattern of stressors.

Some individuals are also more likely to develop long-term problems under stress than others. This may be linked, in part, to coping skills and the presence of particular resources.

Individual characteristics that have been identified as improving a person's ability to handle life stress include higher levels of optimism, greater psychological control or mastery, increased self-esteem, and better social support.

A major development in stress research was the discovery that a particular form of a particular gene (the 5HTTLPR gene) was linked to how likely it was that people would become depressed in the face of life stress.

It is now widely accepted that our genetic makeup can render us more or less "stress-sensitive."

The amount of stress we experience early in life may also make us more sensitive to stress later on. The effects of stress may be cumulative, with each stressful experience serving to make the system more reactive.

Stress tolerance refers to a person's ability to withstand stress without becoming seriously impaired.

Stressful experiences may also create a self-perpetuating cycle by changing how we think about, or appraise, the things that happen to use. Studies have shown that stressful situations may be related to or intensified by a person's cognitions.

This may explain why people with a history of depression tend to experience negative events as more stressful than other people do.

c. Characteristics of Stressors

At some level we all intuitively understand what makes one stressor more serious than another.

The key factors involve

The severity of the stressor

Its chronicity (how long it lasts)

Its timing

How closely it affects our own lives

How expected it is

How controllable it is

The Experience of Crisis

Most of us experience occasional periods of especially acute (sudden and intense) stress. The term crisis is used to refer to times when a stressful situation threatens to exceed or exceeds the adaptive capacities of a person or a group.

d. Measuring Life Stress

The stress from life changes can trigger problems, even in disorders. The faster life changes occur, the greater the stress that is experienced.

Social Readjustment Rating Scale- self-report checklist of fairly common, stressful life experiences

Life Events and Difficulties Schedule-interview based approach

e. Resilience

After experiencing a potentially traumatic event, some people function well and experience very few symptoms in the following weeks and months. This kind of healthy psychological and physical functioning after a potentially traumatic event is called resilience.

Resilience is the most common reaction following loss or trauma. There is no single factor that predicts resilience. Rather, resilience is linked to a variety of different characteristics and resources.

Being a male, being older, and being well educated.

Having more economic resources.

Being a positive person.

Being self-confident and people who view themselves in an overly positive light

2. Stress and the Stress Response

Faced with the threat of a perceived stressor, the body undergoes a cascade of biological changes.

Two distinct systems are involved here.

The sympathetic-adernomedullary (SAM) system is designed to mobilize resources and prepare for a flight-or-flight response.

The stress response beings in the hypothalamus, which stimulates the sympathetic nervous system (SNS). This, in turn, causes the inner portion of the adrenal glands (the adrenal medulla) to secrete adrenaline (epinephrine) and noradrenaline (norepinephrine).

As these circulate through the blood, they cause an increase in heart rate. They also get the body to metabolize glucose more rapidly.

The hypothalamus-pituitary-adrenal (HPA) system- in addition to stimulating the SNS, the hypothalamus releases a hormone called "corticotrophin-releasing hormone" (CRH).

Traveling in the blood, this hormone stimulates the pituitary gland, which then secretes adrenocorticotrophic hormone (ACTHH).

This induces the adrenal cortex (the outer portion of the adrenal gland) to produce the stress hormones called glucocorticoids. The stress glucocorticoid that is produced is called cortisol.

Cortisol prepares the body for flight or flight. It also inhibits the innate immune response.

If the cortisol response is not shut off, cortisol can damage brain cells, especially in the hippocampus. Stress is very bad for your brain.

a. Biological Costs of Stress

The biological cost of adapting to stress is called the allostatic load.

When we are relaxed and not experiencing stress, our allostatic load is low.

When we are stressed and feeling pressured, our allostatic load will be higher.

b. The Mind-Body Connection

The link between stress and physical illness involves diseases that are not directly related to nervous system activity. This suggests that stress may cause an overall vulnerability to disease by compromising immune functioning.

Psychoneuroimmunology is the study of the interaction between the nervous system and the immune system.

Evidence continues to grow that the brain influences the immune system and that the immune system influences the brain.

We have already seen that glucocorticoids can cause stress-induced immunosuppression. This can be adaptive. It makes sense that longer-term stress might create problems for the immune system.

c. Understanding the Immune System

The immune system protects the body from such things as viruses and bacteria.

The front line of defense in the immune system is the white blood cells. These leukocytes (or lymphocytes) are produced in the bone marrow and then stored in various places throughout the body, such as the spleen and the lymph nodes.

There are two important types of leukocytes

B-cell (because it matures in the bone marrow) produces specific antibodies that are designed to respond to specific antigens.

Antigens are foreign bodies such as viruses and bacteria, as well as internal invaders such as tumors and cancer cells.

When a B-cell recognizes an antigen, it begins to divide and to produce antibodies that circulate in the blood.

T-cell (matures in the thymus) is an important endocrine gland.

Each T-cell has receptors on its surface that recognize one specific type of antigen. The T-cells are unable to recognize antigens by themselves. They become activated when immune cells called macrophages direct antigens and start to engulf and digest them. To activate the T-cells, the macrophages release a chemical known as interleukin-1. With the help of the macrophages, the T-cells become activated and are able to begin to destroy antigens.

An important component of the immune system response involves cytokines. They are small protein molecules that serve as chemical messengers and allow immune cells to communicate with each other. They play an important role in mediating the inflammatory and immune response. Cytokines also send signals to the brain.

Pro-inflammatory cytokines help us deal with challenges to our immune system by augmenting the immune response.

Anti-inflammatory cytokines decrease or dampen the response that the immune system makes.

d. Stress, Depression, and the Immune System

Stress is linked to suppression of the immune system.

Although short-term stress compromises the immune stem, it is the more enduring stressor that are associated with the most global immunosuppression.

Although there is a great deal of evidence linking stress to suppression of the immune system, researchers are becoming aware that both chronic stress and depression may also enhance certain immune responses, although not in a good way.

The potential for psychological factors to influence our health and for our health to affect our psychological well-being is becoming ever more apparent.

Correlational research studies are being done which show that chronic stress and depression can result in the immune system going out of balance in ways that may compromise health.

3. Stress and Physical Health

Because the brain influences the immune system, psychological factors are of great importance to our health and well-being.

There is now a growing interest in positive psychology. This school of psychology focuses on human traits and resources such am humor, gratitude, and compassion that might have direct implications for our physical and mental well-being.

When participants were asked to be forgiving, they did indeed report more feelings of empathy and forgiveness.

When they asked to ruminate and be unforgiving, participants reported that they felt more negative, angry, sad, aroused, and out of control.

Forgiving those who have offended us may lower our stress levels and enhance our well-being.

4. Cardiovascular Disease

Because cardiovascular disease is the leading cause of death in the US, and because the impact of stress on the heart has been well researched, it is used to illustrate the many links between psychological factors and physical disease.

a. Hypertension

Hypertension is having a persisting systolic blood pressure of 140 or more and a diastolic blood pressure of 90 or higher.

Normal blood pressure should be below 120/80.

A small percentage of cases of hypertension are caused by distinct medical problems. In the majority of cases there is no specific physical cause. This is referred to as essential hypertension. Hypertension is an insidious and dangerous disorder.

Many clinicians and investigators think that hypertension begins when a person has a biological tendency toward high cardiovascular reactivity to stress. This might be considered to represent a diathesis, or vulnerability factor.

Hypertension and African Americans

African Americans have much higher rates of hypertension than European Americans.

Higher levels of stress from such factors as inner-city living, economic disadvantage, exposure to violence, and race-based discrimination may play a role in this. Lifestyle may also be a factor. Biological factors likely also play a role.

b. Coronary Heart Disease

Coronary heart disease (CHD) is a potentially lethal blockage of the arteries that supply blood to the heart muscle, or myocardium.

c. Risk and Causal Factors in Cardiovascular Disease

Chronic and Acute Stress

Stress increases the risk of having a heart attack. Everyday forms of stress can also elevate risk for CHD and death.

A risk factor is a variable that increases the likelihood of a specific outcome occurring at a later time.

Personality

A Type A behavior pattern is characterized by excessive competitive drive, extreme commitment to work, impatience or time urgency, and hostility.

Type D personality type- people with this have a tendency to experience negative emotions and also to feel insecure and anxious.

Depression

Depression appears to be a risk factor for the development of CHD.