The Body's Response to stress: Key terms
Stress- this is experienced when a person's perceived environmental, social and physical demands exceed their perceived ability to cope. Stress is often then strongly influenced by our perception of a situation rather than a situation itself. Fight or flight- this means that in a stressful situation, the body reacts in a way that causes the person to be able to either fight or run away.
The Body's Response to stress: Acute stress
Acute stress- immediate or short term stress
The immediate stressor's activate the autonomic nervous system (ANS). The ANS is divided into the sympathetic branch (SNS) and the parasympathetic branch.When a person is exposed to acute stress, the SNS is activated which prepares the body for fight or flight. This response also happens because of the sympathetic adrenal medullary system (SAM) which together with the SNS makes the sympathomedullary pathway.
Noradrenaline is the neurotransmitter released by the SNS to activate the internal body organs. At the same time that the SNS is activated, the SAM system releases adrenaline into the bloodstream.
Neurons from the SNS travel to the adrenal medulla and when activated this releases adrenaline into the bloodstream. Effects: boosts the supply of oxygen and glucose to the brain and muscles, suppresses non emergency bodily processes such as digestion.
The Body's Response to stress: Chronic stress
Chronic stress- long term or ongoing stress
Chronic stress activates the pituitary adrenal system( HPA) which controls the levels of cortisol in the body. The HPA is much less easy to activate than the SAM system.
When stressors are perceived by the brain, a message passes to the hypothalamus - this is the control system for most of the body's hormonal systems. Activation of the hypothalamus leads to the release of corticotrophin releasing factor (CRF). CRF causes the pituitary gland to produce and release adrenocorticotrophic hormone (ACTH). Cortisol released by the adrenal cortex is responsible for several stress related effects in the body such as a quick burst of energy and a lower sensitivity to pain.
The Body's Response to stress: Individual differen
TAYLOR ET AL. (2000): found that men usually react with a fight or flight response, where as women react with a tend or befriend in a stressful situation. Taylor found that higher levels of the hormone oxytocin, produced in both men and women, were associated with reduced cortisol responses to stress. Male hormones appear to reduce the effect of oxytocin, but the female hormone oestrogen amplifies it. As a result men are more likely to develop to stress- related disorders than women. It is thought that this could explain why women live an average of 7 and a half years longer than men.
The Body's Response to stress: Consequences
When the stress response system is regularly activated, the cardiovascular system begins to suffer from abnormal wear and tear. The increased blood pressure ( which is an effect of SNS activation) can lead to physical damage in the blood vessel linings.
Although cortisol assists the body in fighting viral infection or healing damaged tissue, too much cortisol suppresses the immune response, shutting down the process that fights infection.
Stress-related illness: The immune system
Acute Stressors: Examination stress
KIECOLT-GLASER ET AL. (1984): carried out a natural experiment investigating stress and the effect on the immune system in medical students. Blood samples were taken a month before the examination period. Immune system function was measured by NK cell activity. NK cell activity was significantly reduced in the blood sample taken during the exam period. This suggests that short term stressors reduce immune system functioning, increasing vulnerability to illness.
MARUCHA ET AL. (1998): looked at exam related immune changes on the rate at which a wound heals. Marucha inflicted a punch biopsy on students either before the summer holidays or 3 days before an exam. The wounds given before the exam took 40% longer to heal than those given before the summer holiday.
Stress-related illness: The immune system
Chronic Stressors: Relationship Stress
KIECOLT- GLASER ET AL. (2005): tested the impact of interpersonal conflict on wound healing within marital relationships. She found that blister wounds on the arms of married couples healed more slowly when they had discussions which were conflicting rather than supportive.
KIECOLT- GLASER ET AL. (1987): compared women separated from their partners were matched married controls. They found poorer immune system functioning in women who had separated during the last year.
MALARKEY ET AL. (1994): studied 90 newlywed couples over a 24 hour period. They were asked to discuss and resolve marital issue likely to produce conflict. Marital conflict produced significant changes in adrenaline and noradrenaline which could lead to poorer immune functioning.
Stress-related illness: The immune system
The effects of stress can sometimes enhance the immune system
EVANS ET AL. (1994) looked at the activity of the antibody slgA which helps protect against infection. Evans arranged for students to give talks to other students causing acute stress. These students showed a slight increase in slgA whereas levels of slgA decreased during exam periods which stretched over long periods of time (chronic stress)
EVANS ET AL. (1997): proposes that stress may have 2 effects on the immune system- up regulation (increased efficiency) for short term acute stress and down regulation (decreased efficiency) for chronic stress
Stress-related illness: The immune system
SEGERSTORM AND MILLER (2004):
They conducted a meta-analysis of 293 studies conducted over the past 30 years and found:
- short term acute stressors boost the immune system
- long term chronic stressors led to suppression of the immune system
- the longer the stress, the more the immune system shifted from potentially adaptive changes to potentially detrimental changes.
Stress-related illness: The immune system
LAZARUS (1992): suggests that there are various reasons why a relationship between stress and illness is difficult to establish
- health is affected by many different factors
- health is generally fairly stable and slow to change
- to demonstrate how stress affects long term health would involve continuous measurement over time. This would be expensive and impractical therefore most research is generally conduct per short periods of time
Stress-related illness: The immune system
Research has shown consistent gender and age differences in the stress/immune system relationship. Women show more hormonal changes in the way they react to marital convict. As people age, stress has a greater effect on the immune system functioning making it harder for the body to regulate itself
Real world applications
Has led to many healthy lifestyle programmes. Stress coping behaviours can be taught to groups of all ages. People who use stress coping behaviour generally report an improvement in their physical an psychological well being
Stress-related illness: Cardiovascular and psychia
Stress and cardiovascular disorders
Acute and chronic stress may affect many different aspects of the cardiovascular system such as:
- hypertension (high blood pressure)
- coronary heart disease ( caused by the narrowing of the coronary arteries)
- stroke ( caused by disruption of blood flow to the brain)
Stress activates the sympathetic branch (SNS) leading to a constriction of the blood vessels and a rise in blood pressure and heart rate. An increase in the heart rate may wear away the lining of the blood vessels. Stress also leads to an increase in glucose levels which can cause clumps that block the blood vessels.
Cardiovascular disorders and anger (acute stress)
WILLIAMS (2000): conducted a study to see whether anger was linked to heart disease. 13,000 participants completed a 10 question anger scale, none of the participants had any heart problems at the time of the questionnaire. 6 years later the health of the participants was checked again; 256 had experienced heart attacks. Those who had scored highly on the anger questions were over 2 and a half times more likely to have a heart problem than those with the lowest anger ratings.
This suggests that anger may lead to cardiovascular disorders.
Cardiovascular disorders and work- related stress
RUSSEK (1962): looked at heart disease in medical professionals. One group were designated as high stress while others were classed as low stress. Russek found that those who were designated high stress such as GPs and anaesthetists had greater heart disease (11.9%) than those with lower stress such as pathologists and dermatologists (3.2%).
This supports the view that stress is linked to heart disease.
The effects of stress on existing conditions
SHEPS ET AL. (2002): Conducted a landmark study, the first study to show that stress can be fatal for people with existing heart disease. They focused their research on volunteers with reduced blood flow to the heart. They gave 173 men and women a variety of psychological tests including public speaking. Their blood pressure soared dramatically and some heart started to beat erratically . Of all the participants 44% who had shown the erratic heartbeats died within the next 3 to 4 years compared with just 18% who had not.
This shows that psychological stress can dramatically increase the risk of death in people with poor coronary artery circulation
ORTH-GOMER ET AL. (2000): showed that among married women, marital conflict was associated with a 2.9 fold increase in recurrent events (Eg heart attacks) for women with existing coronary heart disease.
Stress and depression
BROWN AND HARRIS (1978): found that women who suffered from chronic stress conditions were more likely to develop depression. They also reported that working class mothers were more prone to depression than middle class mothers as they had to leave their children while they go to work.
MELCHIOR ET AL. (2007): carried out a survey over a year in which 1000 people aged 32 in a wide range of jobs took part. They found that 15% in high stress jobs suffered a first episode of depression or anxiety during that year compared with 8% in low stress jobs. Women were generally more affected than men.
Stress and other disorders
ROHLF AND BENNET (2005) : found that 1 in 10 workers whose occupation required euthanizing animals experienced moderate symptoms of PITS (preparation induced traumatic stress- this is when in your job you are expected to kill i.e. soldier, executioner)
STUEVE ET AL. (1998) compared the role of stressful life events causing depression, schizophrenia and other disorders. They found that stressful events were only associated with depression and not with other disorders.
Problems with determining a causal link between stress and depression include:
- it is often not possible to assess whether stressful events before diagnosis of a psychiatric disorder have caused the disorder or have been a consequence of a person's deteriorating state.
- most studies have used retrospective methodology where the recall of events can be somewhat unreliable
- although the relationship between stress and depression has been demonstrated by researchers, others (e.g. RABKIN 1993) claim that the effects are small, accounting for less than 10% of the variance observed.
Stress: Life Changes
Life changes are those that require a big transition in some aspects of our lives such as getting married, dealing with loss, etc.
HOLMES AND RAHE (1967): tested the idea that life changes are related to physical illness and in order to test this, they cam up with the social readjustment rating scale (SRRS). This was based on 43 life events taken from their analysis of 5000 patient records. 400 participants were asked to rate different events from 1 - 100 with 50 for marriage being the baseline value. They found death of spouse required the most readjustment and so it has a score of 100 and minor violations of the law had the lowest score of 11. Scores for all participants were totalled and averaged to produce life change units (LCUs) for each life event.
Stress: Life changes
RAHE ET AL. (1970): used the SRRS to test the hypothesis that the number of life changes positively correlates with illness.
A military version of the SRRS was given to 2700 men from the US navy. The men filled in the questionnaire before a tour of duty and noted all the life experiences they had had in the last 6 months. An illness score was calculated by monitoring and scoring all illnesses during the tour of duty for each man (7 months). Rahe found a positive correlation between LCU and illness score of +118. Given the number of participants this strong correlation is significant. The findings support the hypothesis.
MICHAEL AND BEN-ZUR (2007) : studied 130 men and women, half of whom had recently been divorced and half recently widowed. They looked at levels of life satisfaction, in the widowed group this was found to be higher before their bereavement than after the loss. Divorced individuals showed the opposite pattern after separation from their partners. They had higher levels of satisfaction after the divorce than before.
Evaluation of Life changes Approach
Life changes and daily hassles
LAZARUS (1990) : suggests that life changes are rare in the average persons lives and that it is the daily hassles that damage health.
DELONGIS ET AL. (1988) : studied 75 married couples, they gave them a life events questionnaire and a hassles and uplift scale. They found no relationship but did find a positive correlation between hassles and next day health problems.
The SRRS ignores the fact that life changes have a different effect on different people.
Most studies between life changes and illness have produced correlational data and not causal data.
The hassles and Uplifts Scales (HSUP) measures a persons attitudes towards daily situations. Instead of focusing on more stressful life events it provides a way of evaluating the positive and negative events that occur daily in our lives.
BOUTEYRE ET AL. (2007) : investigated the relationship between daily hassles and the mental health of students during the transition from school to university. Results showed that 41% of the students had suffered from depressive symptoms and there was a positive correlation between scores on the hassle test and the incidence of depressive symptoms.
GERVAIS (2005) : asked nurses to keep diaries for a month recording all their daily hassles and uplifts while at work. They were also asked to rate their own performance. At the end of the month it was found that daily hassles increase job strain and decrease job performance. Nurses felt that some of the uplifts counteracted the hassles
Daily Hassles versus Life Changes
RUFFIN (1993): found that daily hassles were linked to greater psychological and physical dysfunction than major negative life events.
FLETT ET AL. (1995) : a study of 320 students read a scenario describing an individual who had experienced either a major life event or daily hassles. They then rated the amount of support that the person would receive and seek from others. Those who had suffered from a major life event gave a higher rating in seeking and receiving support. The findings suggest that compared to major life events, the negative influence on daily hassles may be due to the reduced social support received from others.
Evaluation of Research into Daily Hassles
Explaining Daily Hassles
The accumulation effect- an accumulation of minor daily stressors creates irritation, frustrations and overloads which then result in a more serious stress reactions such as anxiety and depression
The amplification effect - chronic stress due to major life changes may make people more vulnerable to daily hassles as it amplifies a life change to make it more stressful.
The problems of retrospective recall - participants are asked to rate the hassles experienced
What does Research tell us- most of the data is correlational, this means that we cannot draw causal conclusions about the relationship between daily hassles and well being.
MILLER ET AL. (1992) : studied 250 people over 50 years old and their relationships with their pets. They found that pets appear to serve different roles for female and male owners. For females pets are associated with uplifts but males associate them with hassles.
Real world applications
GULIAN ET AL. (1990) : found that participants who reported a difficult day at work reported higher levels of stress on their commute home. When unresolved non driving hassles are carried forward into driving situation events such as mechanical failure and the actions of other road users are more likely to be interpreted as stressful by the driver.
Workplace stress- Aspects of our working environment that we experience as stressful and which causes a stress reaction in our body.
Workload and Control
MARMOT ET AL. (1997) investigated the job-strain model of workplace stress. He suggested that in the civil service, higher grade employees would experience high workload and low grade civil servants would experience low job control. Therefore both grades are likely to experience a different type of stress. For his study, 7372 participants answered a questionnaire on workload, control and amount of social support. They were also checked for signs of cardiovascular disease. 5 years later participants were re-assessed.
Workload and Control
Marmot found no link between high workload & stress related illness and concluded that workload demand wasn't a significant factor in stress. Other studies that looked at demand: (JOHANSSON ET AL. 1978) looked at the effects of doing a repetitive job that require continuous attention. The high risk group (sawyers in a mill) had a stressful job with a fast pace and responsibility. They were found to have higher illness rates and higher levels of adrenaline than the low risk group (maintenance workers). The high risk group also had higher levels of stress hormones on work days than any other day.
Marmot found that participants in the higher grades of the civil service had developed the fewest cardiovascular problems whereas those in the lower grades had developed it the most. Those in lower grades expressed a lower sense of job control and had the poorest social support.
Marmot suggested that lack of control was a workplace stressor.
SCHAUBROECK ET AL. (2001) found that some workers react differently to lack of control. For people who view negative work outcomes as being their fault, the control can actually worsen the unhealthy effects of stress.
Real World Applications
RITEVANEN ET AL. (2007) investigated the effect of aerobic fitness reducing the physiological stress response teachers experience during working hours. 26 male and female participants took part in the study and were involved in exercise tests, measurements of physiological responses such as levels of adrenaline etc and measurement of perceived stress. Results showed that those with the highest levels of fitness had lower levels of heart rate, muscle tension and perceived stress.
Consequences Of Workplace Stress
Stress and Coronary Heart Disease
KIVIMAKE ET AL. (2006): meta analysis of 14 studies looking at the relative risk of coronary heart disease and work stress. Found that employees with high levels of stress were more than 50% likely to develop CHD.
Workplace stress and mental health
- Opportunity for control- do situations offer the opportunity for personal control over activities and events?
- Opportunity for skill use- does the job allow for the use of existing skills or the development of new skills?
- Opportunity for interpersonal contact- important for meeting needs of friendship and social support.
Personality Factors and stress - Type A and B
Type A characteristics:
- competitiveness and achievement striving
- impatience and time urgency
- hostility and aggressiveness
Type B Characteristics
- lack of type A characteristics
- patient, relaxed and easy going
Western Collaborative group study showed that twice as many type A participants had died of cardiovascular problems than type B. Type A's also had higher blood pressure and higher cholesterol.
The Hardy Personality
KOBASA AND MADDI (1977) suggested that some people are more psychologically hardy than others
- Control- hardy people see themselves as being in control of their lives
- Commitment- hardy people are involved in the world around them and have a strong sense of purpose
- Challenge- hardy people see life challenges as problems to overcome rather than as threats or stressors. They enjoy change as an opportunity to develop.
KOBASA (1979): studied 800 American business executives assessing stress (SRRS), about 150 were assessed as being high stress and out of these some had low illness records whereas others had high. Kobasa proposed that the hardy personality encourages resilience.
Evaluation of the Hardy Personality
Hardiness and negative affectivity
Some critics argue that the characteristics of the hardy personality can be more simply explained by the concept of negative affectivity as found by WATSON AND CLARK (1984). NA and hardiness correlate reasonably well suggesting the hardy individuals are simply those who are low on NA.
Problems of Measurement
Most research support for a link between hardiness and health has been obtained through self report questionnaires. A new questionnaire has been brought out but not all the problems have been resolved eg some studies show low internal reliability for the challenge component of hardiness.
Psychological Methods of Stress Management
Stress Inoculation training
MEICHENBAUM (1985): believed we could change the way we think about stress using SIT ( Stress inoculation training) as a form of CBT: cognitive behavioural therapy
- conceptualisation phase - the therapist and client establish a relationship and the client is educated about the nature and impact of stress. Eg the client is taught to view perceived threats as problems to be solved
- skills acquistion phase (and rehearsal) - coping skills are taught and practised in the clinic and then gradually rehearsed in life. These skills include positive thinking, relaxation, social skills, methods of attention or diversion etc. The skills are both cognitive and behavioral.
- application phase (and follow through) - clients are given opportunities to apply the coping skills in different situations which become increasingly stressful. Clients may even be asked to help train others, booster sessions are offered later on.
Strengths and Weaknesses of SIT
- Effectiveness: MEICHENBAUM (1977): compared SIT with another treatment (desensitisation). patients used either treatment to deal with snake phobias. He found that both forms reduced the phobia but SIT was better because it helped patients deal with a second non treated phobia. SHEEHY AND HORAN (2004): examined SIT on anxiety, stress and academic performance of law students. results showed that that all participants who received SIT dis[played lower levels of anxiety and stress.
- Preparation for Future stressors: it gives the client skills to deal with other stressors as it focuses on long lasting effectiveness.
- Time Consuming and requires high motivation
- Unnecessarily complex
- Focusing : the client is taught how to recognise the physiological signs of stress such as muscle tension and increased heart rate and also to identify the sources of this stress.
- Reliving stress encounters : the client relives stress encounters and is helped to analysis these situations and their response to them. This gives them an insight into their current coping strategies and how they might be more effective than they thought.
- Self Improvement : the insights can now be used to move forward and learn new techniques of dealing with stress. In particular the client is taught to focus on seeing stressors as challenges that they can take control of, rather than problems that they must give in to.
Hardiness training can help at risk students to stay in and graduate . It has been used effectively by Olympic swimmers to ensure that they are committed to the challenge of increased performance levels and are able to control their daily lives. However it cannot be seen as a rapid solution to stress management
Physiological methods of stress management
Drug Therapies - BZs
Benzodiazepines are most commonly used to treat anxiety and stress as they slow down the activity of the central nervous system. BZs enhance the effect of GABA which is the bodys natural form of anxiety relief. As a result the brains output of exicatory neurotransmitters is reduced and the person feels calmer. BZs also reduce any increased serotonin activity which has an arousing effect in the brain and this then reduces anxeity.
Beta Blockers BBs
BBs reduce the effect of adrenaline and noradrenaline by binding and blocking receptors of parts of the body and cells of the heart that are usually stimulated during arousal. This causes thes heart to beat slower and results in a fall of blood pressure. The person feels calmer and less anxious.
Strengths and Weaknesses of Drug treatments
- Effectiveness- KAHN found that BZs were significantly superior to placebo's, BBs have been found to help musicians by reducing anxiety
- Ease of Use- requires little effort from user
- Addiction- patients can exhibit withdrawal symptoms
- Side Effects- paradoxical symptoms such as increased aggressiveness and cognitive side effects- memory impairment. Most people who take BBs do not experience any side effects
- Treating the symptoms rather than the problem