The Role of Stress in Illness - Immunosuppression

Question 1

What is the immune system responsible for?

Answer 1

It is our main defence against infection, seeking out and destroying foreign agents.

Question 1

What is an antigen?

Answer 1

Bacteria, viruses, fungi (mould, yeast)

Question 2

Which type of blood cell is vital to the effective functioning of the immune system?

Answer 2

White blood cells are crucial in the body’s fight against bacteria, viruses and fungi.

Question 3

If stress persists it can lead to immunosuppression. What is meant by immunosuppression?

Answer 3

This refers to the weakening of the immune system, making the body more prone to infection.

Question 4

How does chronic stress result in immunosuppression?

Answer 4

Corticosteroids/cortisol produced as a result of chronic stress can shrink the thymus gland, preventing the growth of T cells.

Question 5

What are the potential consequences of chronic immunosuppression?

Answer 5

Possibility of more frequent illnesses and infection.

Question 6

what was the aim of Kiecolt-Glaser et al. (1984) study

Answer 6

Aim: To study the effects of examination stress on immune system functioning

Question 7

what was the procedure of Kiecolt-Glaser et al. (1984) study

Answer 7

Procedure:
Natural experiment
Sample: Volunteer sample of 75 medical students
To assess immune function, blood samples were taken (measuring T and NK cell activity).
Blood samples were taken one month before their final examinations (low stress) and during their examinations (high stress).
They also completed a questionnaire about life events (the SRRS) and loneliness.

Question 8

what were the findings of Kiecolt-Glaser et al. (1984) study

Answer 8

T and NK cell activity was significantly lower in the second sample taken during examinations, compared to one month previous.

T and NK cell was lowest amongst those who reported high levels of life events and loneliness.

Question 9

what were the conclusions of Kiecolt-Glaser et al. (1984) study

Answer 9

Examination stress results in immunosuppression, making the individual more susceptible to illness and infection.

Immune function is also affected by psychological variables i.e. life events and loneliness, which may make individuals more vulnerable to short-term stressors such as examinations.

Question 10

what was the ecological validity like in Kiecolt-Glaser et al. (1984) study

Answer 10

High ecological validity – they studied a natural stressor e.g. examination stress, as opposed to artificially induced stressors, making it possible to generalise the findings to everyday life.

Question 11

Explain the difficulty of establishing a cause-effect relationship i.e. between exam stress and immune system functioning, from this research. Are there any other factors that might have affected the functioning of the students’ immune system?

Answer 11

It is difficult to establish a cause-effect relationship because this study was not conducted under carefully controlled laboratory conditions, therefore we cannot be certain that examination stress had a direct effect on the student’s T cell production. Other non-controlled situational variables might play a part

Question 12

Why might there be difficulty in generalising the results of this study to other people (population validity)? Comment on the use of a volunteer sampling method – what are the drawbacks of this sampling method?

Answer 12

Low population validity: they only sampled medical students, who are a distinct group of individuals – they may respond differently to stress compared with non-students. This makes it difficult to generalise the findings beyond individuals studying medicine as they are potentially not representative of the general population.

Question 13

what is the immune system a key part of

Answer 13

The immune system plays a crucial part in wound healing as it is responsible for producing cytokines, which are proteins that cause the tissue surrounding a wound to become inflamed, which encourages healing.

Question 14

what did Kiecolt-Glaser et al. further research investigate

Answer 14

Kiecolt-Glaser et al. (1995) investigated the direct effects of stress on the immune system by looking at how quickly wounds heal. They recruited a group of 13 women through a newspaper advertisement (volunteer sample) who were caring for relatives suffering from senile dementia, a task which has been shown to be associated with chronic stress and matched (a matched participants design) them with a control group of 13 women. All participants were given a wound – a ‘punch biopsy’ which is a cut of 3.5mm just below the elbow. In addition, participants were assessed in terms of levels of cytokines (biochemical substances which regulate the body’s immune response). Participants also completed a stress scale.

Question 15

what were the findings of Kiecolt-Glaser et al. further research

Answer 15

• Wounds took an average of 9 days longer to heal in the carers than the control group. - Cytokine levels were lower in the carers than the control group, suggesting immunosuppression. - Carers reported higher levels of stress on the stress scale.

Question 16

what were the drawbacks of Kiecolt-Glaser et al. further research

Answer 16

However, the matching of ppts was rather inexact and the researchers didn’t control for whether or not the ppts smoked or were married.
This could have affected their responses to stress.

Question 17

what were the conclusions of Kiecolt-Glaser et al. further research

Answer 17

Chronic stress suppresses immune system functioning.

Question 18

Evaluate the relationship between stress and the immune system (Evans)

Answer 18

Evans et al. (1994) looked at the activity of one particular antibody, slgA, which coats the mucous surfaces of the mouth, lungs and stomach and helps protect against infection.
The researchers arranged for students to give talks to other students, an activity that was considered to be acutely stressful.
Levels of slgA were measured before giving these talks and also during the examination period, which lasted for many weeks (chronic stress).
They found that levels of slgA in the students rose before giving the mildly stressful talk, but decreased during the exam period.

Question 19

what do the studies between stress and the immune system show

Answer 19

These studies suggests that ACUTE STRESS can actually improve immune system functioning and that it is actually CHRONIC STRESS that has a damaging effect on the immune system.

Question 20

However, Lazarus (1992) argued that it is difficult to establish a relationship between stress and illness because…

Answer 20

Health is affected by many different factors besides stress, such as…….
Lifestyle factors: Diet; Exercise; Smoking; Drinking; Sleeping habits

Health is generally fairly stable and slow to change, making it difficult to demonstrate that exposure to certain stressors cause a change in health.

The long-term study of stress would be expensive, time-consuming and impractical.

Question 21

what are individual differences in the research

Answer 21

Kiecolt-Glaser et al. (2003) found that females show severe hormonal and immune system changes in response to marital conflict.
As people age, stress has a greater effect on immune system functioning, making it harder for the body to regulate itself (Segerstrom and Miller, 2004)
Other research has also suggested that personality type can determine the impact that stress has on immune system functioning i.e. those with a Type A personality are more likely to experience the negative effects of stress.