- Created by: Georgina Pellow
- Created on: 09-02-14 20:39
Body's Response to Stress
- Sympathomedullary Pathway - Deals with acute stress, preparing the body for figh or flight.
Stressor > Hypothalamus > Brainstem > ANS > Adrenal medula > Release of adrenaline/noradrenaline
- Petuitory Adrenal System - Deals with chronic stress, taking 20 mins for the process to complete.
Stressor > Hypothalamus > Pituitary gland > ACTH (via blood stream) > Adrenal cortex > Release of hormones (corticosteriods)
- ANS - Consists of the sympathetic and the parasympathetic branch. The sympathetic branch increases heart rate, inhibits saliva, releases glucose etc. while the parasympathetic branch does the opposite bringing the body back to homeostasis.
There may be individual differences. Taylor found that men responded to stress with fight of flight while women responded with tend and befriend. Oxytocin is secreted by both men and women in response to stress but in men the effect is reduced, in women it's increased (due to other hormones). As a result, men are more vulnerable to the negative effects of stress.
There are consequences to the stress response. Increased bp can damage the lining of blood vessels eventually leading to heart disease. Similarly, too much cortisol can supress the immune response. Suggesting that you are vulnerable to illness e.g. infection.
Stress and the Immune System
- Kiecolt Glaser (relationship stress) - Tested the impact of interpersonal conflict on wound healing, blisters on the arms of married couples took longer to heal after a conflicting discussion. (chronic)
- Marucha (exam stress) - Looked at whether exam related immune changes have effect on the rate at which wounds heal. Inflicted a punch biopsy in the mauths of students over the summer and 3 days before the exam. Wounds inflicted days before took 40% longer to heal. (acute)
- Kieclot Glaser (exam stress) - Conducted a natural experiment on 75 medical students to see if the stress of important exams had an effect on the functioning of the immune system. Took blood samples a month before the exam (low stress) and during (high stress). NK cell activity reduced during high stress showing that exams reduce immune system functioning, you become vulnerable to illness. (acute)
There are reasons why a relationshipbetween stress and illness is hard to establish. Health is afffected by many different factors including genetic material and lifestyle as suggested by Lozarus.
Stress can enhance the immune system. Evens looked at an antigen called sigA which protects against infection. Students were asked to present a paper to the class and it was found that is increased the levels od sigA.
Researchhas shown differences between age and gender and stress and the immune system. Women show more immunological changes in reaction to marital conflict. As people age stress has a greater effect on the immune system as it becomes harder to regulate.
Stress Related Illness
- Williams (cardiovascular) - Study to see if anger was linked to heart disease. 15000 p's given a 10 question anger scale (none had heart disease), 6 years later 256 p's had experienced a heart attack. Scoring high made them 2.5 times more likely to suffer suggesting there is a link.
- Russek (cardiovascular) - Looked at heart disease in medical professionals. GP's had high stress while Pathologists had low stress. Heart disease is greater in high stress jobs, shown by GP's having 11.9% and Pathologists having 3.2%.
There are individual differences. Research suggests that the sympathertic branch of the ANS in some individuals is more reactive than in others meaning some people respomd to stress with greater increase in bp and heart rate. This can lead to more damage to the cardiovascular system.
- Brown and Harris (depression) - Women who suffer with chronic stress are more likely to develop depression, for example working class women are more prone to depression due to the stress of leaving their children in the care of others.
- Mechior (depression) - Conducted a survey over a period of a year among 1000 people aged 32 from a wide range of jobs. 15% had high stress jobs and suffered with depression that year, compared to 8% with low stress jobs. Women generally worse affected than men.
For a person to develop a psychiatric disorder they must possess a biological vulnerability to that disoreder (diathesis). An individuals vulnerability is determined by genetic or early biological factors. Stress can have an impact on this vulnerability and could trigger the onset of a disorder or worsen the cause. This suggests that the link between depression and stress is the other way round.
There are problemswith determining a link between stress and depression. It's not possible to assess whether stressful events before being diagnosed are the cause or consequence of a person's deteriorating state. This suggests that stress insn't always directly linked to depression.
- Holmes and Rahe - Created the SRRS (social readjustment rating scal) based on 43 life events from analysis of over 5000 patient records. 400 p's scored each event in terms of the baseline (marriage - 50).
300+ high risk of illness / 150+ moderate risk of illness
- Rahe - Used a military version of the SRRS to test the number of life events that positively corrilated with illness. It was given to the men before going on a tour of duty, noting down events from the past 6 months. Illness score positively correlates (+0.118). Change rather than negativity causes stress.
(Life changes correlated with physical illness)
The SRRS ignors that life changes affect each individual differently. Death of a spouse will have a devastating effect on the survivng partner but death of an elderly spouse who suffered a painful illness may not be as stressful. You cannot assume that each life event will have the same impact on each individual.
Life changes rely on people's memory being accurate and consistent. Brown suggested that people who are unwell are more likely to report stressful events than those not ill. Therefore, it may lack validity.
The reliability of retrospective reports has been questioned. Rahe found test-retestreliability varies depending on the time interval between them. However, most researchers have reported acceptable levels of reliability for retrospective reports of life events.
- Hassels and Uplifts Scale - Developed `by Delongis measures p's attitudes towards daily situations evaluating both positive and negative events (contains 53 items)
- Gervais - Asked nurses to record hassels, uplifts and feelings in a diary for a month (rate their performance). At the end of that month it was clear dialy hassles increase job strain, decrease performance. Nurses felt that uplifts counteracted negative effects of daily hassles and increased performance.
- Bouteyre - Investigated relationship between daily hassels and mental health of students during the transition from school to uni. 41% of the students suffered from symptoms of depression. There's a positive correlation between scores on hassels scale and incident of depressive symptoms.
When using these scales there are problems with recall. Retrospective reporting is unreliable as people may remember hassels more than uplifts or they may have poor memory. Researchers overcome this by using a diary method where they can rate stressors and feelings.
A further problem is deciding how useful the research is. Most data obtained is correlational meaning we cannot draw causal conclusions about the relationahip between daily hassels and well being. As a result, we would be unwise to ignore the message in the research.
The amplification effect. A life change can cause you and others areound you to be more vulnerable to daily hassels, this life change amplifies each daily hassel which can lead to chronic stress or depression.
- Johansson - Investigated whether work stressors such as repetitiveness and high levels of responsibility increase stress related physiological arousal and illness. A high risk group of 14 finishers in a Sweedish Saw Mill were compared with a low risk group of 10 cleaners. The high risk group secreted higher levels of stress hormones (found in urine samples) and higher levels of stress related illness. The combination of work stressors can lead to chronic physiological arousal leading to stress related illness.
... evaluation to complete
- Type A and Type B - Type A - an incessant struggle to achieve more and more in less and less time. 3 major characteristics; competative, impatient and aggressive (all of which rais blood pressure and levels of stress hormones. Type B - opposite of type A. 3 majorcharacteristics; relaxed, patient and easy going (all of which make a person less vulnerable to stress-related illness).
- Friedman and Rossenman - Set up the Western Collaborative Group study assessing 3000 men aged 39-59, they were examined for signs of CHD. And personalities were assessed using an interview that tried to elicit type A behaviour. 12.8% type A had a heart attack compared to 6% type B. 2.7% type A had a fatal heart attack compared to 1.1% type B.
High stress/low illness group = 3 C's
- Hardy - Characterised by the 3 C's; control (they feel in control of their lives), commitment (involved with the world around them and feel they have a purpose) and challange (they see life problems as something to overcome). If all 3 are present then they provide defence against the negative effects of stress.
- Kobasa - Studied 800 American buisness executives using the SRRS, 150 were classified as high stress, some had low records of illness but some had high. This suggestssomething else was modifying the effects of stress as individuals within the same stress levels had different illness records. Suggesting a hardy personality encourages resilience.
There is a link between CHD and Type A. Myrtek carried out a meta analysis of 35 studies on the topic finding that the hostility characteristic was associated with CHD. However, there is no other evidence to suggest a link.
Most research supports a link between hardiness and health but relies on data obtained through self report techniques which can be biased. Recent efforet led to the development of personal views which addresses many of the criticisms but not all. For example, some studies show low internal validity.
Some psychologists srgue that control, commitment and challange can be more easily explained as the consequence of a bad mood. Individuals in high negative mood are more likely to report distress, dwell on failures and focus on the negative. This was suggested by Watson and Clarke.
- SIT (Stress Innoculation Therapy - A form of CBT (Cognitive Behavioural Therapy) developed by Michenbaum. The idea that we can change the way we think as negative thinking leads to negative outcomes e.g. anxiety whereas positive thinking leads to positive outcomes and attitudes. It it believed that this will reduce the stress response and help us cope in the future. There are 3 main stages:
1) Conceptualisation - A relationship between therapist and client is established, the client is educated about the nature and effects of (impact of) stress.
2) Skills Acquisition - Coping skills tailored to the client are taught and practiced e.g. positive thonking, relaxation.
3) Application - Clients are encouraged to use these skills in stressful situations.
A strength of SIT is that it's effective. Meichenbaum compared SIT with sytematic desensitisation, both forms reduced phobia but SIT was better as it can help you deal with more than one. This shows that innoculation by SIT can protect against future stressors.
SIT prepares you for future stressors. It provides clients with skills and confidence to cope, providing long lasting effectiveness.
A weakness of SIT is that it's time consuming and requires high motivation. It requires time, effort, motivation and money. It may be more effective but it's complexity makes it lengthy.
- Hardiness Training - developed by Kobasa. 3 main stages:
1) Focusing - Clients taught to see signs of stress e.g. increased heart rate and identify the source of the stress.
2) Reliving stress encounters - Clients relive stress encounters and helped to analyse them, giving insight into current coping stratgies.
3) Self Improvement - The client is taught to see stressors as challenges to take control of and overcome (start small).
It has been shown that hardiness training works. The student support services of a college in America offered hardiness training to high risk students. It was found that it helped them to stay and graduate as they mastered any stressors they encountered.
A strength of hardiness training is that it's effective. It has been used by olympic swimmers to ensure they are committed to the challenge of increased performance levels and are able to control stressful aspects of their lives. Showing that it can help.
There are problems with hardiness training. It must forst adress the basic aspect of personality and learned habits of coping that are difficult to change. Therefore, it cannot be seen as a rapid solution.
- BZ's (benzodiazopines) - Reduced anxiety and stress by slowing down the activity of the CNS. They effect the neurons reducing the brains output of neurotransmitter making a person feel calmer. GABA is a neurotransmitter that reacts onto neurons' receptors allowing cl- in making it harder for the neuron to excite. BZ's enhance GABA action by increasing the flow of cl- into the neuron. Serotonin has an arousing effect on the brain but BZ's reduce any raised seratonin activity, reducing anxiety.
- BB's (beta blockers) - Stress arouses the sympathetic nerveous stsyem leading to increased heart rate,blood pressure and cortisol levels. BB's reduce the activity of adrenaline/noradrenaline by binding to receprors on cells of the heart stimulated during arousal, this blocks the receptors making it harder to stimulate the heart resulting in reduced blood pressure, reducing the strain on the heart making a person calmer and less anxious.
A strength of drug treatment is that they are effective. Kahn followed nearlynearly 250 patients over 8 weeks finding that BZ's were significantly superior to placebo's (have no effect on the body). They are able to reduce general anxiety associated with stressful situations.
A strength of drug treatments is that they're easy to use. Taking drugs requires little effort as you only need to remember to take them in comparison to SIT which requires a lot of time, effort and motivation from the client.
A weakness of drug treatments is that there could be side effects. The use of BZ's could result in symptoms such as aggressiveness and impaired memory. However, people who take BB's don't experience any side effects.