Psychological Factors and Health
Did You Know That…
Module 4.1: Physical, Emotional, and Cognitive Effects of Stress Module 4.2: Module 4.3: Factors in Health and Illness Psychological Factors in Physical Health Problems Module 4.4: Adjustment and Modern Life: Becoming an Active Health Consumer RECITE! RECITE! RECITE!
DID YOU KNOW THAT…
• Fear can give you indigestion? (p.122) • At any given moment — even as you read this page — millions of microscopic warriors within your body are carrying out search-and-destroy missions against foreign agents? (p. 123) • Writing about the stresses in your life may help protect your health? (p. 125) • Blowing things out of proportion can give you a headache? (p. 132) • Chronic anger may damage your heart? (p.136) • Nearly two-thirds of cancer deaths in the United States are linked to two forms of behavior we can control: smoking and diet? (p. 140) • Earning a degree may not only help you prepare for a better job, but it may save your life? (p. 143)
ome of us are our own best friends. We mind what we eat, we exercise regularly, and we monitor the sources of stress in our lives so that we can regulate their impact. Some of us are our own worst enemies. We share contaminated needles or engage in reckless sexual behavior despite knowledge that HIV/AIDS can be transmitted in these ways. We eat foods high in cholesterol and fats despite knowledge that we heighten the risks of coronary heart disease and cancer. And, of course, we continue to smoke even though we know full well that we are not invulnerable. As we shall see in this chapter, scientists have learned that psychological factors, such as stress and behavior patterns, play major roles in determining our vulnerability to potentially life-threatening diseases, such as heart disease, cancer, and diabetes, as well as the length and quality of our lives. In the following chapter we examine the health beneﬁts of developing healthier eating, ﬁtness, and sleep habits. In this chapter, we consider ways in which our behavior patterns either help safeguard our health or put our health in jeopardy. We also explore the psychology of adjustment to physical illness, such as how people cope when faced with a serious illness.
Physical, Emotional, and Cognitive Effects of Stress
I I I I
What is health psychology? What is the general adaptation syndrome? What are the emotional and cognitive effects of stress? How does the immune system work and how does stress affect it?
Chapter 4 / Psychological Factors and Health Health psychology The ﬁeld of psychology that studies the relationships between psychological factors (e.g., attitudes, beliefs, situational inﬂuences, and overt behavior patterns) and the prevention and treatment of physical illness.
Health psychology is the subﬁeld of psychology that studies relationships between psychological factors and the prevention and treatment of physical health problems (Revenson & Baum, 2001). Health psychologists study the ways in which • Psychological factors such as stress, behavior patterns, and attitudes lead to or aggravate physical health problems. • People can cope with stress. • Stress and pathogens (disease-causing organisms such as bacteria and viruses) interact to inﬂuence the immune system. • People decide whether to seek health care. • Psychological forms of intervention such as health education (for example, concerning nutrition, smoking, and exercise) and behavior modiﬁcation programs can contribute to physical health. One of the major areas of research that health psychologists study is the effects of stress on physical health. Exposure to high levels of stress taxes our coping resources and puts us at risk of developing physical disorders ranging from headaches to coronary heart disease. In this module we take a closer look at how stress affects the body.
The Body’s Response to Stress
Stress is more than a psychological event. It is more than “knowing” it is there; it is more than “feeling” pushed and pulled. Stress also has clear effects on the body. Famed stress researcher Hans Selye outlined the sequence of changes that occur in the body in response to stress, which he called the general adaptation syndrome (GAS), or stress response. It appears that the body under persistent stress is like a clock with an alarm system that does not shut off until its energy has been depleted.
General adaptation syndrome (GAS) Selye’s term for a hypothesized three-stage response to stress. Alarm reaction The ﬁrst stage of the GAS, which is “triggered” by the impact of a stressor and characterized by sympathetic activity. Fight-or-ﬂight reaction Cannon’s term for an innate adaptive response to the perception of danger. Endocrine system A body system involved in regulating many bodily processes and consisting of ductless glands that empty their secretions, called hormones, directly into the bloodstream. Sympathetic division The division of the ANS that is most active during activities and emotional responses — such as anxiety and fear — that spend the body’s reserves of energy. Autonomic nervous system (ANS) The part of the nervous system that regulates glands and involuntary activities such as heartbeat, respiration, digestion, and dilation of the pupils of the eyes. Parasympathetic division The division of the ANS that is most active during processes that restore the body’s reserves of energy, such as digestion.
The General Adaptation Syndrome
Selye (1976), who was playfully called “Dr. Stress,” observed that the body’s response to different stressors shows certain similarities, whether the stressor is a bacterial invasion, perceived danger, or a major life change. For this reason, he labeled this response the general adaptation syndrome (GAS). The GAS is a cluster of bodily changes that occurs in three stages: an alarm reaction, a resistance stage, and an exhaustion stage. The Alarm Reaction The alarm reaction is the body’s initial response to a stressor. This reaction mobilizes or arouses the body in preparation to defend itself against a stressor. Early in the twentieth century, physiologist Walter B. Cannon (1932) termed this alarm system the ﬁght-or-ﬂight reaction. The alarm reaction is triggered by various types of stressors. It prepares the body to ﬁght or ﬂee from a threatening stressor or source of danger. The alarm reaction involves a number of body changes that are initiated by the brain and further regulated by the endocrine system and the sympathetic division of the autonomic nervous system (ANS). The autonomic nervous system, the part of the nervous system that automatically (“autonomic” means automatic) controls involuntary bodily processes such as heartbeat and respiration, consists of two divisions or branches, the sympathetic division and the parasympathetic division. These divisions (or systems) have largely opposite effects. The sympathetic nervous system accelerates bodily processes, such as heart rate and breathing, and leads to the release of energy from stored reserves during times when the body needs additional oxygen and fuel to work harder or defend itself against threats. The sympathetic nervous system takes control during the alarm reaction. The parasympathetic nervous system tones down states of bodily arousal and controls bodily processes that replenish resources, such as digestion.
Chapter 4 / The Body’s Response to Stress
Hypothalamus Pituitary Thyroid
Glands of the Endocrine System
The endocrine system consists of a network of glands located throughout the body that secrete hormones directly into the bloodstream. The endocrine system plays important roles in reproduction, growth, metabolism, and the body’s response to stress.
Adrenal Pancreas Kidneys Ovaries Uterus Testes
Let us now consider the roles of the endocrine and autonomic nervous systems in the stress response. First, however, you may wish to examine Figures 4.1 and 4.2 to learn more about the glands of the endocrine system and autonomic nervous system. Stress has a domino effect on the endocrine system. A small structure in the brain called the hypothalamus secretes corticotrophin-releasing hormone (CRH). CRH PARASYMPATHETIC BRANCH SYMPATHETIC BRANCH
Hypothalamus A small, pea-sized structure in the brain involved in regulating many bodily processes, including hunger, sleep, emotions, and body temperature.
Constricts pupil Stimulates salivation Constricts bronchi (breathe less rapidly)
Dilates pupil Inhibits salivation Relaxes bronchi (breathe more rapidly)
Stimulates gall bladder
The Autonomic Nervous System
The autonomic nervous system helps regulate automatic bodily responses, such as heart rate, respiration, and digestion. The parasympathetic branch or
Stimulates digestive system Contracts bladder Stimulates sex organs (erection) Inhibits digestive activity Relaxes bladder Inhibits sex organs
division of the ANS is generally dominant during activities that replenish the body’s store of energy, such as digestion and rest. The sympathetic branch or division is most active during activities in which the body needs to spend energy, such as ﬁghting or ﬂeeing from a threatening stressor, and when we experience strong emotions such as fear and anger.
Chapter 4 / Psychological Factors and Health
Corticosteroids Hormones produced by the adrenal cortex that increase resistance to stress in ways such as ﬁghting inﬂammation and causing the liver to release stores of sugar. Also called cortical steroids.
What do you experience happening in your body when you are under stress? How do those sensations ﬁt the description of the general adaptation syndrome?
causes the pituitary gland to secrete adrenocorticotrophic hormone (ACTH). ACTH then causes the adrenal cortex, the outer layer of the adrenal glands, to secrete corticosteroids, or steroidal hormones. Corticosteroids help the body resist stress by making nutrients which are stored in the body more available for use in meeting demands for energy that is required to cope with stressful events. However, corticosteroids can be harmful to the cardiovascular system, which is one reason that chronic stress can impair one’s health, and why athletes who use steroids to build the muscle mass can experience cardiovascular problems. Two other hormones that play a major role in the alarm reaction are secreted by the inner part of the adrenal glands, which is called the adrenal medulla. The sympathetic division of the ANS activates the adrenal medulla, causing it to release a mixture of the hormones adrenaline and noradrenaline. This mixture of stress hormones arouses the body by accelerating the heart rate and stimulating the liver to release stored energy in the form of glucose (sugar). This process provides the energy that fuels the ﬁght-or-ﬂight reaction, which activates the body so that it is prepared to ﬁght or ﬂee from a predator. The alarm reaction or ﬁght-or-ﬂight mechanism is like an internal alarm system. It stems from a period in human prehistory when many stressors were life-threatening. Perhaps then it was triggered by the sight of a predator at the edge of a thicket or by a sudden rustling in the undergrowth. Today it may be aroused when you need to “battle” stop-and-go trafﬁc or when you are confronted with an upsetting or challenging event, such as taking an examination. Once the threat is removed, the parasympathetic nervous system takes control and the body returns to a lower state of arousal. Many of the bodily changes that occur in the alarm reaction are outlined in Table 4.1. The Resistance Stage If the alarm reaction mobilizes the body and the stressor is not removed, we enter the adaptation or resistance stage of the GAS. Levels of endocrine and sympathetic nervous system activity are lower than in the alarm reaction but still higher than normal. In this stage the body attempts to restore lost energy and repair bodily damage. The Exhaustion Stage If the stressor is still not dealt with adequately, we may enter the exhaustion stage of the GAS. Individual capacities for resisting stress vary, but the body will eventually become exhausted when stress continues indeﬁnitely. The muscles become fatigued. The body is depleted of the resources required for combating stress. With exhaustion, the parasympathetic nervous system may come to predominate (Figure 4.2). As a result, our heartbeat, respiration rate, and bodily arousal may slow down. It might sound as if we would proﬁt from the respite, but remember that we are still under stresss — possibly an external threat. Continued stress in the exhaustion stage may lead to what Selye terms “diseases of adaptation.” These can range from allergies to hives to even coronary heart disease (CHD) — and, ultimately, death. Later in the chapter we explore a number of these stress-related illnesses. Table 4.1: Components of the Alarm Reaction Corticosteroids are secreted Adrenaline is secreted Noradrenaline is secreted Respiration rate increases Heart rate increases Blood pressure increases Muscles tense Blood shifts from internal organs to the skeletal musculature Digestion is inhibited Sugar is released from the liver Blood clotting increases
Resistance stage The second stage of the GAS, characterized by prolonged sympathetic activity in an effort to restore lost energy and repair damage. Also called the adaptation stage. Exhaustion stage The third stage of the GAS, characterized by weakened resistance and possible deterioration.
Chapter 4 / The Body’s Response to Stress
Adjustment in the New Millennium
“Fight or Flight” or “Tend and Befriend”? Gender Differences in Response to Stress Nearly a century ago, Harvard University physiologist Walter Cannon labeled the body’s response to stress the “ﬁghtor-ﬂight” reaction. He believed that the body was prewired to become mobilized or aroused in preparation for combat when faced with a predator or a competitor, or if the predator was threatening enough, that “discretion” — that is, a “strategic retreat” — would sometimes be the “better part of valour.” The ﬁght-or-ﬂight reaction includes a cascading sequence of bodily changes involving the autonomic nervous and endocrine system, under control of structures in the brain. Fast-forward to our century. UCLA psychologist Shelley Taylor and her colleagues (2000) argue that at least half of us are more likely to tend to the kids or “interface” with family and friends in the face of stress than to ﬁght or ﬂee. Which half of us would that be? The female half. Taylor explains that her interest in the ﬁght-or-ﬂight reaction was prompted by an offhand remark of a student who had noticed that nearly all of the rats in studies of the effects of stress on animals were male. Taylor did an overview of the research on stress with humans and noted that prior to 1995, when federal agencies began requiring more equal representation of women if they were to fund research, only 17% of the subjects were female. Quite a gender gap — and one that had allowed researchers to ignore the question as to whether females responded to stress in the same way as males. Taylor and her colleagues then dug more deeply into the literature and found that “men and women do have some reliably different responses to stress” (Taylor et al., 2000). She called the characteristic response to stress in women the “tend-and-befriend” response. It involves nurturing and seeking the support of others rather than ﬁghting or ﬂeeing. Taylor and her colleagues reviewed studies that showed that when women faced a threat, a disaster, or even an especially bad day at the ofﬁce, they often responded by caring for their children and seeking contact and support from others, particularly other women. After a bad day at the ofﬁce, men are more likely to withdraw from the family or start arguments. This response may be prewired in female humans and in females of other mammalian species. Evolutionary psychologists might suggest that the tend-and-befriend response might have become sealed in our genes because it promotes the survival of females who are tending to their offspring. (Females who choose to ﬁght may die or at least be separated from their offspring — no evolutionary brass ring here.) Gender differences in behavior are frequently connected with gender differences in hormones and other biological
“Fight-or-Flight” or “Tend-and-Befriend”?
Walter Cannon labeled the body’s response to stress the “ﬁghtor-ﬂight” reaction. He thought that evolution prewired the body to become mobilized in preparation for combat or rapid retreat when faced with a threat. It has been assumed that this reaction applies to both men and women, but research by Shelley Taylor and her colleagues suggests that women may be “prewired” to take care of others (“tend”) or afﬁliate with others (“befriend”) when they encounter threats.
factors. This one is no different. Taylor and her colleagues point to the effects of the pituitary hormone oxytocin. This hormone stimulates labor and causes the breasts to eject milk when women nurse. It is also connected with nurturing behaviors such as afﬁliating with and cuddling one’s young in many mammals (Taylor et al., 2000). The literature also shows that when oxytocin is released during stress, it tends to have a calming effect on both rats and humans, making them less afraid and more social. But wait a minute! Men also release oxytocin when they are under stress. So why the gender difference? The answer may lie in the presence of other hormones, the sex hormones estrogen and testosterone. Female have more estrogen than males do, and estrogen appears to enhance the effects of oxytocin. Males, on the other hand, have more testosterone than females, and testosterone may mitigate the effects of oxytocin by prompting feelings of self-conﬁdence (which may be exaggerated) and fostering aggression (Sullivan, 2000). It is thus possible that males are more aggressive than females under stress because of biological differences in the balance of hormones in their bodies, while females are more afﬁliative and nurturant. It makes evolutionary sense, at least. In order to perpetuate the human species and even make it tougher as the generations progress, it takes only a few tough men (does this sound like a commercial for the Marines?) to impregnate a large number of women.
Chapter 4 / Psychological Factors and Health
But men, even tough ones, may not outlive women. “Men are more likely than women to respond to stressful experiences by developing certain stress-related disorders, including hypertension, aggressive behavior, or abuse of alcohol or hard drugs,” Taylor added in a UCLA press release (May 18, 2000). “Because the tend-and-befriend regulatory system may, in some ways, protect women against stress, this biobehavioral pattern may provide insights into why women live an average of seven and a half years longer than men.” Not all psychologists agree with an evolutionary or biological explanation. Psychologist Alice Eagly (2000) allows
that gender differences in response to stress may be rooted in hormones but suggests we consider an alternative: Differences may reﬂect learning and cultural conditioning. “I think we have a certain amount of evidence that women are in some sense more afﬁliative, but what that’s due to becomes the question. Is it biologically hard-wired? Or is it because women have more family responsibility and preparation for that in their development? That is the big question for psychologists.” A very big question, indeed.
Hormones Substances secreted by an endocrine gland that regulates various body functions. (From the Greek horman, meaning “to stimulate” or “to excite.”) Hypertension High blood pressure.
Emotional Effects of Stress
Emotions color our lives. We are green with envy, red with anger, blue with sorrow. The poets paint a thoughtful mood as a brown study. Positive emotions such as love and desire can ﬁll our days with pleasure, but negative emotions, such as those induced by stress, can ﬁll us with dread and make each day an intolerable chore. Let us consider three important emotional responses to stress: anxiety, anger, and depression. Anxiety Anxiety tends to occur in response to threats posed by such stressors as physical danger, loss, and failure. Anxiety is a stressor in its own right (it places demands on us) as well as an emotional response to stress. Psychologists frequently distinguish between trait anxiety and state anxiety. Trait anxiety is a personality variable. People with trait anxiety have persistent feelings of dread and foreboding — cognitions that something terrible is about to happen. They are chronically worried and concerned. State anxiety is a temporary condition of arousal that is triggered by a speciﬁc situation, such as the eve of a ﬁnal exam, a big date, a job interview, or a visit to the dentist. On a biological level, sympathetic nervous system arousal in response to stress is associated with physical symptoms such as rapid heartbeat and breathing, sweating, and muscle tension. These physical responses are often accompanied by strong emotions such as terror, fright, anxiety, rage, or anger. (Think back to a time when you experienced fear or anger. Was your heart beating rapidly? Did you break out in a sweat — perhaps a cold sweat?) Because sympathetic nervous activation predominates when you are under stress, digestion is inhibited. Thus, fear may be accompanied by indigestion. Anger Anger usually occurs in response to stressors such as frustration and social provocation. Hostility differs from anger in that it is an enduring trait. Anger usually involves cognitions (thoughts and beliefs) to the effect that the world should not thwart our efforts to meet our needs (in the case of frustration) or that another person has no right to treat us in a certain way (in the case of a social provocation). Like anxiety, it is accompanied by strong bodily responses, such as rapid heartbeat and breathing. Depression Depression usually occurs in response to stressors such as the loss of a friend, lover, or relative; to failure; to inactivity or lack of stimulation; and to prolonged stress. Why does depression sometimes stem from inactivity and lack of stimulation? People have needs for stimulation, and some “stress,” which Selye referred to as eustress, is desirable and healthful. Why does depression stem from prolonged exposure to stress? On a biological level, depression is characterized by parasympathetic dominance, and parasympathetic activity is characteristic of the exhaustion stage of the GAS.
Trait anxiety Anxiety as a personality variable, or persistent trait. State anxiety A temporary condition of anxiety that may be attributed to a situation.
Chapter 4 / Effects of Stress on the Immune System
Emotions and Behavior Emotions motivate certain kinds of behavior. Negative emotions such as anxiety, anger, and depression can motivate us to behave in maladaptive ways. For example, anxiety tends to motivate escape behavior; anger, aggressive behavior; and depression, withdrawal. It is helpful for us to perceive negative emotional responses as signs that something is wrong, to learn what we can about the sources of stress, and then to plan behavior that will enable us to remove or buffer stressors. But when our emotions “run too high,” they can disrupt our cognitive processes and interfere with adaptive behavior.
Cognitive Effects of Stress
Under stress, we may have difﬁculty thinking clearly or remaining focused on the tasks at hand. The high levels of bodily arousal that characterize the alarm reaction can impair memory functioning and problem-solving ability. On examinations — a source of stress that can trigger the alarm reaction — you may have experienced such high levels of negative arousal (anxiety) that you are unable to recall material you were sure you had banked in memory. Afterward, you might think, “I just drew a blank.” Also, in a state of high arousal, we may become so focused on our body responses or expectations of failure or doom that we cannot keep our thoughts on the problems at hand.
Have you ever found it difﬁcult to concentrate or think clearly when you are under stress? When you reﬂect on it, does it seem that your “level of arousal” might have had anything to do with the confusion?
Effects of Stress on the Immune System
Given the complexity of the human body and the fast pace of scientiﬁc change, we often feel that we are dependent on trained professionals to cope with illness. Yet we actually do most of this coping by ourselves, by means of the immune system. The immune system has several functions that combat disease (Delves & Roitt, 2000). One of these is the production of white blood cells, which engulf and kill pathogens such as bacteria, fungi, and viruses, and worn-out and cancerous body cells. The technical term for white blood cells is leukocytes. Leukocytes carry on microscopic warfare. They engage in search-and-destroy missions in which they “recognize” and eradicate fore...