Download fighting to stay well

Stress and Health: Exploring the Links
By: Steven F. Maier and Mark Laudenslager
From: Psychology Today, August, 1985.
Exercises: J. Geffen
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1.
After his daughter died, the middle-aged doctor could hardly contain his grief.
He was disconsolate and felt during the next year as if he were “giving himself
cancer”. He managed, by denying both her existence and her death, to continue to
work for the next few years, but had continual infections and a nagging cough.
2.
Three years after her death, anticipating the girl’s birthday, the doctor began
again to grieve. At the same time, for a three-month stretch, work was particularly
stressful.
3.
On the eve of his daughter’s birthday, the doctor, barely able to breathe, was
admitted to the local hospital’s intensive care unit. After a lung biopsy revealed that
he had a very rare type of pneumonia, he was given antibiotics and promptly
responded. Despite his apparent recovery, his infection had made him suspicious.
After researching in his local medical library, the doctor, a bisexual, diagnosed his
condition as AIDS, a diagnosis later confirmed by a laboratory workup.
4.
The doctor’s true story is a new variation on a very old theme. Whether as
folklore or as the anecdotes of today’s health professionals, the essence of his story
has been repeatedly retold: Disease and even death can follow in the wake of grief,
unrequited love, financial losses, humiliation and other emotionally painful events.
We’ve all heard, for instance, that stress can cause ulcers and heart attacks. Now
evidence is mounting that vulnerability to infectious disease – and even cancer – may
be affected by how people react to stress.
5.
But only some individuals seem to be vulnerable, and only under certain
circumstances. Today’s research challenge is to find out what accounts for these
differences and, if possible, to find ways to keep more people well despite life’s stings
and setbacks.
6.
Researchers were once reluctant to associate psychological states with
infectious diseases because they could not imagine a physiological connection
between them. But evidence of such connections has grown in the past decades. And
researchers in the emerging field of behavioral immunology are beginning to explain
how psychological events can affect physical health.
7.
Infectious diseases provide a particularly good example. Since they are caused
by exposure to identifiable pathogens such as viruses and bacteria, their origins seem
quite simple and biological, not psychological. But that’s not the whole story. Only a
fraction of those infected with a pathogen become ill, and psychological factors may
play a major role in determining who does and does not get sick.
Stress and Health: Exploring the Links / 2
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8.
A number of investigators have studied how some life stresses (such as job
change, the birth of a child or marital difficulties) are related to the development of
infectious diseases by asking sick people to list stressful life changes they went
through before the disease. Their responses are compared with those of people who do
not have the illness. The results have revealed that high levels of stress frequently
precede illness.
9.
Other researchers use a more informative technique, measuring life stress in
healthy people, then tracking them to see who develops an infectious disease and how
stress is related to that illness. For example, in 1979, Stanislav Kasl, Alfred Evans and
James Neiderman at the Yale School of Medicine studied the development of
infectious mononucleosis in a class of West Point cadets. All entering cadets were
screened for immunity and susceptibility to the disease, caused by the Epstein-Barr
Virus (EBV). Those whose blood contained the antibody to EBV were considered
immune, while those without the antibody were classified as susceptible. The
susceptible cadets had their blood tested periodically. The investigators also studied
interview data on the cadets’ expectations and family backgrounds, obtained by West
Point during routine testing of new cadets.
10. About one-fifth of the susceptible cadets became infected each year. However,
only about one-quarter of the infected cadets developed mono’s clinical symptoms.
Several psychological factors were involved: Cadets who had described their fathers
essentially as “overachievers” were more likely to develop symptoms. Moreover, the
cadets most likely to become ill most strongly wanted a military career but performed
poorly academically, just the ones who ought to be under the greatest stress.
11. Studies such as these strongly support the idea that psychological factors can
influence the development of infectious disease, presumably by altering the immune
system, the body’s major defense against pathogens (see “Fighting to Stay Well”
box).
12. More than 40 years ago, Hans Selye, a pioneer of stress research, noticed an
increase in adrenal-gland activity and a decrease in immune-system activity in
response to physical stress. Modern immunology has confirmed Selye’s findings. In
animal studies, stressors include electric shock, high-intensity sounds, burn injuries
and physical restraint. In studies of humans, more complex psychological stressors,
such as a number of life changes, sleep deprivation, bereavement and depression, have
been associated with lowered immune response. Certainly, in both animals and
humans, the link between stressors and impaired immune functioning is quite strong.
But why, then, do only some stressed individuals become ill?
13. When considering how humans react to life events, we must distinguish
between exposure to a potential stressor and actual physical and psychological
responses to it. Stress does not simply result from a particular negative event, even a
loved one’s death. Rather, it results from a complex interaction between the event and
a variety of psychological factors, such as the person’s expectations and experience
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and the presence or absence of a network of caring people. Such factors may be
important in determining whether a negative event will affect immune functioning and
disease.
14. Research with both animals and humans indicates that an individual’s control
over an event is particularly important in determining its psychological and
physiological effects. Research by psychologist Jay M. Weiss of Duke University
School of Medicine has shown, for example, that if animals have control over an
unpleasant stimulus, they do not develop ulcers, depressed appetite, sleep disturbances
or brain-chemistry changes characteristic of stress responses.
15. The effects of stressor control on behavior are also striking. Animals that have
been in an uncontrollable stressful situation show a variety of disturbances when later
confronted with stressors that can be controlled by escape or avoidance. Most
importantly, they behave passively and do not learn to avoid the stressors. Such
behavioural changes, resulting from exposure to uncontrollable stressors, are part of a
syndrome called “learned helplessness” by psychologist Martin Seligman of the
University of Pennsylvania and one of us (Maier) when we collaborated in studying
this response.
16. Learned-helplessness effects occur in humans, too, when they lack control over
stressful events. But sometimes, just thinking that control is possible, even if it isn’t,
can prevent adverse stress effects. Essentially, people’s beliefs that they can control a
stressful event affect how they will react.
17. In 1972, psychologists David Glass and Jerome Singer gave two groups of
people a number of mental tasks to do, while exposing them to loud, unpleasant
noises. The first group was not told of any way to stop the noise. People in the second
group were told they could turn off the noise by pressing a button, although the
experimenter would prefer that they did not. This choice of being able to stop the
noise gave the second group a feeling of control. Later both groups were given a
second task of proofreading, without any noise disturbance. In this experiment, the
group who earlier could not control the noise made more errors than the group who
had felt in control.
18. Clearly, the fact and the belief that stressors can be controlled are important in
determining psychological and physiological reactions to stressful situations. But how
do these factors affect the immune system and the development of disease?
19. One clue comes from research done in 1979 that showed that in animals
exposed to uncontrollable stressors, implanted tumors grew more rapidly and were
less often rejected than in those exposed to stressors they could control.
20. Tumor growth and rejection are affected by the immune system but also by
many nonimmune processes. Thus, we and our colleagues at the University of
Colorado at Boulder set out to determine directly whether the ability to control a
stressor affects the immune system’s activity. We reasoned that if we could show in
animals that a purely psychological factor – being able to control a stressor – altered
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immune function, we could determine which emotional factors were involved, which
immune-system changes occurred and which physiological mechanisms produced
them.
21. We studied this in rats by exposing them to controllable and uncontrollable
stressors and comparing their immune-system responses. Rats in the controllablestressor group were put in a box with a wheel in it. We attached to their tails
electrodes that could give a mild, intermittent shock to one tail portion. The apparatus
was arranged so that the rats could shut off the shock whenever it occurred by turning
the wheel; naturally, they quickly learned the trick.
22. Rats in the uncontrollable-stressor group were put in an identical set-up, but the
shocks were actually controlled by the behavior of the rats in the first group. Nothing
the rats in the second group did affected the pattern of shocks. Two other groups were
used for comparison: those exposed to the apparatus without shock, and those
unstressed at all.
23. As a measure of immune-system response, we studied how readily the rats’ Tcells (a type of lymphocyte, a key component of the immune system) multiplied when
“challenged” by mitogens. Like antigens, the foreign invaders T-cells normally fight
in the body, mitogens stimulate these cells to proliferate extensively.
24. We found that in response to the mitogens, T-cells from rats that could control
the shock multiplied as readily as did those from unstressed rats. However, T-cells
from rats exposed to identical but uncontrollable shock only multiplied weakly. Thus,
the shocks did interfere with the immune response only in rats that could not control
them.
25. We wondered whether our results might extend to another immune-system
measure: the tumor-killing ability of natural killer (NK) cells, which play a key role in
tumor surveillance. In collaboration with psychologists John Liebeskind and Yehuda
Shavit of the University of California at Los Angeles, we removed and studied NK
cells from rats exposed to controllable, uncontrollable or no stress. NK cells from
unstressed rats or those that could control the stressor killed tumor cells normally,
while NK cells from rats exposed to an uncontrollable stressor were less able to kill
tumor cells.
26. These studies are the only ones to manipulate directly the effect of
controllability of stressors on immune function. But many other situations involving
an uncontrollable stressor have been studied. One is the separation of infants from
parents, an especially obvious and potentially important example. In 1982, one of us
(Laudenslager), working with psychiatrist Martin Reite of the University of Colorado
Health Sciences Center, set out to study whether separating an infant from its mother
would alter immune functioning. Since human subjects could not be used, the nextbest subject was chosen: the monkey. Two weeks after 6-month-old monkeys had
been separated from their mothers, the youngsters’ immune-system responses were
lessened, as indicated by lowered lymphocyte proliferation. Similar separation studies
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by psychologists Christopher Coe and Seymour Levine at Stanford University in
California have shown lowered ability to generate antibodies to specific viral
invaders. Thus, stressors do not have to be simple physical events such as noise or
shock to suppress immunity. They can be as psychological as an infant’s “grief” at
being separated from its mother.
27. Are human reactions similar? It appears that they may be. We can infer from
various studies that the immune responses of some people may be suppressed when
they cannot control severe negative events. The death of a spouse is perhaps the most
potent uncontrollable and negative event for many of us. Roger Bartrop of the
University of New South Wales and his colleagues in 1977 monitored several aspects
of immunity in 26 people soon after their spouses died. Six weeks after the death,
immune function was impaired: Lymphocyte proliferation was lowered.
28. Other studies have shown that some bereaved people may become seriously
depressed, and that some depressed people tend to show less immunity to disease.
Perhaps bereaved people who feel able to control their negative circumstances are
more protected than others from depression and lessened immune responses.
29. A recent study by psychiatrist Steven Locke and his colleagues at Harvard
University Medical School supports this sort of argument. Healthy volunteers were
given questionnaires on life stresses within the past month and the past year, as well
as a check-list of common psychological complaints. A blood sample was taken and
NK-cell activity was assessed. Surprisingly, the occurrence of life stresses, even very
severe ones, did not predict NK-cell activity. Many people, despite repeated
upheavals, did not show abnormally low levels of NK-cell activity. What was critical,
however, was how people reacted emotionally to stressful events. Those who reported
many life stresses as well as high levels of anxiety and depression had the lowest NKcell activity. Those with similarly extensive life stresses but little anxiety and
depression showed the highest NK-cell activity, even higher than in people who
experienced few life stresses and were low in anxiety and depression.
30. Locke and his colleagues speculate that people who, despite many negative life
events, do not react with anxiety or depression can cope well, a psychological
characteristic reflected in their very high NK-cell activity. Conversely, those who
react with anxiety and depression seem to have poor coping skills, reflected as well in
their lowered NK-cell activity.
31. Psychologist Sandra Levy has reached similar conclusions in her exploratory
study of how personality factors are related to NK-cell activity and the spread of
cancer to the lymph nodes in women treated for breast cancer. Women who accepted
the disease and adjusted to their condition showed lower NK-cell activity than those
who responded with anger and agitation.
32. Levy argues that acceptance of the cancer and adjustment to the situation may
reflect a belief that nothing can be done about the disease, a helpless reaction. In
contrast, anger and disturbance may reflect attempts to alter the course of the disease.
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Thus, beliefs in possible control might have profoundly affected NK-cell activity in
these women. When it was high, lymph-node involvement was less likely.
33. Much of what has been discovered through behavioural immunology still needs
to be clarified, verified and more fully explained. Immunology itself is a rapidly
developing field, and current understanding of the immune response and ways to
measure it is changing daily. We expect the field of behavioural immunology to
reveal additional links between behavior and health, yielding more comprehensive
approaches to treating illness and new ways to help people maintain good health.
FIGHTING TO STAY WELL
The immune system is burdened with the momentous task of keeping us healthy
by recognizing and destroying foreign materials such as bacteria, viruses, fungi and
tumors. Its workhorses are white blood cells – more than a thousand billion of them –
which are based in the lymph system and circulate through the blood stream. These
cells belong to two major classes: lymphocytes – B-cells, T-cells and natural killer
(NK) cells – and phagocytes.
In general, the job of lymphocytes is to recognize invaders (antigens) as foreign;
to multiply after recognition so more invaders can be identified; and to generate
chemicals, such as the antibodies produced by B-cells, that can reach and neutralize or
destroy antigens.
Most lymphocytes need the back-up of phagocytes, which are attracted to
antigens being attacked. The phagocytes then finish off their destruction.
However, some lymphocytes, such as NK cells, can fight their own battles
directly with antigens. They can spontaneously destroy tumor and other cells and
seem less specific than other lymphocytes. These cells have received a lot of attention
recently because they may play a key role in tumor rejection. Recent human studies
have suggested that when NK cells are very active, cancers may be less likely to
develop. NK cells appear to form part of an early immune surveillance system
preventing the growth and spread of tumors, but how is still unclear.
Steven F. Maier is a professor of psychology at the University of
Colorado at Boulder. Mark Laudenslager is an assistant research
psychologist at the University of Denver and assistant clinical professor
of psychiatry at the University of Colorado Health Sciences Center.
Stress and Health: Exploring the Links / 7
Answer in your own words.
Answer the question below in English.
1.
What does the title itself suggest?
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
Answer the question below in Hebrew.
2.
Does the story of the middle-aged doctor who had lost his daughter and
eventually contracted AIDS – paragraphs 1-3 – necessarily support the main
thesis of this article? Substantiate your answer.
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
Answer the question below in English.
3.
What does the fact that only a fraction of those infected with a pathogen become
ill – paragraphs 6-7 – suggest?
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
Answer the question below in English.
4.
What conclusions does the experiment conducted among West Point cadets –
paragraphs 9-10 – lead to?
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
5.
Name some researchers who point to an immediate relationship between stress
and susceptibility to disease.
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
Answer the question below in Hebrew.
6.
What is meant by “learned helplessness” – paragraph 15?
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
Stress and Health: Exploring the Links / 8
Answer the question below in English.
7.
How did the exposure to uncontrollable stressors – paragraph 19 – affect the
animals experimented upon?
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
Choose the best answer.
8.
What do the experiments described in paragraphs 21-24 illustrate?
Answer:
a. They suggest that controllable stressors have a paralysing effect upon the
immune system.
b. They point to the helplessness of animals when exposed to controllable
stressors.
c. They suggest that the uncontrollable stressors both activate and stimulate
the immune system.
d. They suggest that exposure to controllable stressors does not reduce the
resistance of the immune system.
Answer the question below in English.
9.
How does paragraph 25 relate to the previous three paragraphs?
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
Complete the sentence below.
10. Bereavement – paragraph 27 – must surely be considered _________________
________________________________________________________________
________________________________________________________________
Answer the question below in English.
11. How does the acceptance of and resignation to a particular condition –
paragraph 32 – affect the immune system?
Answer: _________________________________________________________
________________________________________________________________
________________________________________________________________
Answer the question below in Hebrew.
12. Would you consider behavioral immunology a full-fledged discipline?
Substantiate.
Answer: _________________________________________________________
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Stress and Health: Exploring the Links / 9