Stress - Body's response to stress
Acute stress: The Sympathomedullary Pathway
- Sympathetic nervous system - The perception of a stressor leads to the activation of the sympathetic branch of the autonomic nervous system (ANS). This is the 'Fight or Flight' response.
- The Adrenal Medulla* is activated by the sympathetic nervous system (SNS) and triggers the release of adrenaline and noradrenaline. The adrenal medulla is in the adrenal glands just above the kidneys. (*The adrenal medulla is related to SAM)
- Adrenaline prepares the body for the fight or flight response by boosting heart rate, increasing the supply of oxygen and glucose to the brain and suppressing non-emergency processes.
- This activates the 'rest and digest' response. This is the response after the stress; including sexual arousal, salivation, crying, urination, digestion and defecation.
Research into the Sympathomedullary pathway:
- Taylor et al (2000) had found that acute stress produces the fight or flight response in men, but in women it produces the 'tend and befriend' response. This effect is beleived to occur as women produce more oxytocin, which relates to relaxation and nurturing.
Explains different responses in genders and explains why they happen. Doesn't consider evolutionary role or behaviours.
- McCarty (1981) found that blood plasma levels of adrenaline and noradrenaline were equal in rats of varying ages before giving them 1 minute of inescapable foot shock. Older rats had lower levels than younger rats after being shocked. This suggested that diminished response of the pathway explains the reduced capacity of aged animals to adapt to stressful stimulation
Shows different responses to stress in different ages. Lacks ecological validity as it only looks at rats and not humans.
- The gender difference in the activation of the pathway may occur due to women's evolutionary role; caring for offspring. If women fought or fled when in danger, their offspring would be placed in danger.
- The studies into stress responses were mainly conducted on men, as psychologists believed that the monthly fluctuations of hormones in women would create a wide range of stress response. This means that it cannot be generalised to women.
- Much research was conducted on animals which presents an extrapolation problem, as the response to stress in animals does not represent that of humans. Humans have a more cognitive element to their responses.
Chronic Stress: The Pituitary-Adrenal System
(Also known as the hypothalamic-pituitary-adrenal axis: HPA axis)
1. The hypothalamus in the brain produces hormones in response to stress, such as corticotrophin releasing factors (CRF), which stimulate the anterior pituitary gland to secrete its hormones.
2. The pituitary gland releases adrenocorticotrophic hormone (ACTH), which stimulates the adrenal cortex in the adrenal glands.
3. The adrenal cortex releases at least 20 different hormones but the most important being cortisol. Cortisol has a variety of effects.
Research into the pituitary-adrenal system:
- Newcomer et al (1999) found that participants given levels of cortisol high enough to produce a response similar to those of a person experiencing a major life event were significantly poorer at recalling prose passages than participants given cortisol levels only high enough to produce a response similar to someone experiencing a daily hassle. This suggests that stressful stimulation of the system has diverse effects on memory.
This has some ecological validity as it produces real stress responses which are induced by hormones, but some people may have been aware of the laboratory setting and could have adapted their responses in some way.
- Watson et al (2004) compared the system functioning in 26 people with bipolar disorder, 27 with the disorder in remission and 28 healthy controls. There was higher cortisol levels in people with bipolar disorder and in those in remission. This suggests the system dysfunction may be involved in the disease process underlying bipolar disorder.
- There are individual differences with response levels. Mason (1975) found that different individuals produce different levels of stress hormones when exposed to the same stressor.
- People respond in more active ways to stressors involving cognitive and emotional factors. Symington et al (1955) found that conscious terminal cancer patients experienced more stress than those in a coma, as they indulged in a more stressful appraisal of their condition.
- The biological explanation of stress allows accurate, objective measures to be made.
Stress - Stress and the Immune Response.
The immune system/response protects the body from various diseases and germs.
The main components of the system are antibodies and white blood cells (leucocytes). There are different types of leucocytes, including T-cells, B-cells and natural killer cells. These can fight viruses and tumors.
When a person experiences long term chronic stress, they produce constant supplies of adrenaline and cortisol. While these hormones are considered helpful in the the short term, they can have a long term effect on our immune systems. They reduce the activity and production of antibodies and leucocytes, which can render the body defenceless.
- Kiecolt-Glaser et al (1995) gave small wounds to participants and measured how long they took to heal. They had found that the healing process took longer for women who cared for senile relatives. This was supported by other measurements of immune system functioning, indicating that chronic stress lessens the immune systems functioning.
- Cohen et al (1993) exposed participants in his study to the common cold virus. It was found that people who displayed high stress scores were more likely to catch a cold than those displaying lower scores. This suggests that stress depresses the effects of the immune system.
Kiecolt-Glaser (1984) - study the capability of the immune system in people facing stressful situations.
- Blood samples taken from 49 male and 26 female volunteer first year medical students one monthe before final exams and the first day after the exams were sat. These samples were analysed for leucocyte activity.
- Natural killer cells were greatly reduced in the second sample compared to the first. Immune responses were weakest in those scoring highly for loneliness, stressful life events and psychiatric symptoms.
- Concluded that stress is associated with reduced immune function, especially in individuals exposed to particular stressors.
- Stressors were naturally occuring and the IV and DV were not artificially created.
- The participant variables were controlled as the participants were compared to themselves.
- Other non-controlled variables may have played a part in the results, we cannot be sure that the stressors fully change the immune system.
Evaluation for stress and the immune system
- The functioning of the immune system in most stressed individuals is within the normal range, therefore, it is unclear why stress might have such big effects.
- The physiological account does not explain how the stress response varies depending on the type of stressor and individual differences. Mason (1975) found that levels of adrenaline and noradrenaline secretion varied in different people when exposed to situations of fear, anger or uncertainty.
Stress - Sources of Stress
These are occassional events which lead to major adjustments to lifestyle, such as death of a spouse or divorce. There are many variations in the impact life changes can have. For example, a death of a spouse may be devastating to one person but it may be a blessing in disguise for another person. Also, when some life events do not occur, such as getting into university, they can be equally devastating. Scales have been created to messure the stress of life changes, such as the Social Readjustment Rating Scale (SRRS).
- Rahe et al (1970) assessed stress and illness in 2,500 sailors. Just before the tour of duty, they had to fill in a questionnaire relating to any life changes over the past 6 months. This provided a LCU for each of them. A health record was kept on each of them over the next 6 months. A positive correlation of +.118 between LCU's and illnesses was found.
- The SRRS muddles different kinds of life events, most particularly those that you have some control over and those that you do not. It is the latter events that may be most stressful.
- The SRRS does not allow for the fact that different people interpret the same event differently and, therefore, it is not realistic to assign a single number to the experience of stress.
- Studies using the scale have found only a small correlation between life events and illnesses, some studies have found no correalation at all.
- The importance behind the SRRS scale is not through its usefulness, but through its status as a breakthrough. The scale triggered a large amount of research studies to be conducted and encouraged people to make more effective tools. Sarason et al (1978) sought to improve the SRRS by asking people to indicate how desirable or undesirable a life event may be. This is the Life Experiences Survey (LES).
These are small everyday irritations that can produce an elevated level of stress. For example, getting stuck in traffic only lasts for a small part of the day but can prove most stressful and fustrating. Daily hassles, due to their constant nature, are perhaps a better indicator of physical and mental states of well-being. This is because life events can trigger big stress reactions, daily hassles build up, producing an overall hightened level of stress, which presents a serious risk of illness.
The effects of daily hassles can be neutralised by daily uplifts.
- DeLongis et al (1982) studied 100 individuals over 1 year, monitering health, life events, daily hassles and uplifts. They found a significant negative correlation between hassles and health status. There was also a significant negative correlation between hassle intensity and health status, but no significant correlation with uplifts. This suggests that the more daily hassles or intense hassles a person experiences, the lower their health status may be.
- Kanner et al (1981) performed a study of 100 men and women, aged 45-64 years, over 1 year. They confirmed that hassles are correlated with undesirable psychologocal symptoms and that hassles were a more powerful predictor of stress than life events. For instance, divorce can create a number of daily hassles, such as having to cook for oneself. This suggests that daily hassles intervene between critical life events and health, with the collective impact of the hassles being most harmful to health. The effect of uplifts were unclear.
The pressure of work and the work environment are a major cause of stress. Work problems feature both as major life events and as hassles and uplifts. The negative impact of work can seriously affect someones health in the job, including their productivity and absenteeism.
The causes of workplace stress include job uncertainty, organisational change, interpersonal conflicts, sexual harassment, punitive management, work overload, under-utilisation of skills, difficult tasks, decision making lack of support and poor work environments.
The effects of workplace stress include absenteeism, high staff turnover, alcohol and drug abusee and poor performance in terms of quantity and quality.
- Johansson et al (1978) - A high risk group of ten finishers, whose jobs involved repetitiveness and high levels of responsibility, was compared to a low risk group of ten cleaners. Stress related hormones in urine samples were recorded on work days and rest days. Stress related illnesses and amount of days absent were also recorded. The high risk group had higher stress hormone levels then the low risk group. The high risk group had higher stress hormone levels on work days than rest days. The high risk group had more stress related illnesses and had more days absent from work. This suggested that workplace stressors, like repetitiveness and high responsibility, create long term physiological arousal, leading to stress related illnesses and absenteeism.
The stressors in the workplce that were most stressful were not identified.
Individual differences were not accounted for.
A practical application is that employers can reduce workplace illness and ebsenteeism by lessening workplace stressors.
- Workplace stressors are not naturally harmful to health. In fact, the workplace can provide hightened opportunities to increase self esteem, confidence and motivational levels and give individuals a sense of purpose and fulfilment. All these factors can contribute to a better well-being.
- There are individual differences involving workplace stress. Schaubroeck et el (2001) found that some workers are less stress when they have no control or responsibility. In this study, they found that some people had higher immune responses in low control situations. Some people view negative work outcomes as being their fault. For these employees, control can actually exacerbate the unhealthy effects of stress.
Type A & B - Friedman and Rosenman (1959) looked at people who experienced higher levels of stress, calling them personality type A (typically impatient, competitive, time pressured and hostile). Individuals who lack these characteristics and are genrally more relaxed were called type B. Friedman and Reosenman assessed 3,154 healthy men aged 39-59, living around San Francisco in 1960. Eight and a half years later, they found that 257 of the sample had developed CHD. 178 were type A and half as many were type B. 22 years later, 178 of these men had died from CHD; 119 being type A and 95 type B. An explanation for these results 22 years later is that the men had followed health advice and, therefore, even type A individuals were experiencing less stress.
Type C - These individuals cope with stress by suppressing their emotions which leads to chronic stress that affects the functioning of the immune system. Type C is associated with the increased rates of cancer.
Type D - these individuals are generally gloomy, socially inept and worry alot. Denollet et al (1996) interviewed 300 adults (men and women) who had suffered heart attacks. 10 years later, those who had a tendancy to supress emotions (type C) and experience negative emotions (type D) were 4 times more likely to have had a further heart attack.
Hardy personality type - Kobasa et al (1982) found that managers of large companies who were psychologically 'hardy' suffered less illness. The characteristics of hardiness are: greater sense of commitment; seeing stressful situations as a challenge; stronger sense of personal control.
- Some recent reasearch has found that hostility may be the key component in the type A vulnerability to stress (Myrtek, 2001).
- It is unclear whether personality types are a cause or an effect, whether they are directly related to stress responses or whether they are actually indirectly related.
- There is no real evidence that people divide easily into separate personality types. Individuals may have elements of many of these characteristics and indeed labelling people could lead to self-fulfilling prophecies, where people adopt the charactersistics of their label.
Stress - Coping With Stress
Emotion focused and Problem focused
1. Emotion focused
- These tend to reduce the emtion associated with stress. These tend to be physiological methods, such as relaxation. Emotion focus:
- Is useful when the situation itslef cannot be changed
- Often requires less effort, for example taking drugs
- Does not usually provide long term solutions for a particular problem because only the symptoms are dealt with.
- May have a negative effect as it delays the individual dealing with the problem.
2. Problem focused
- This tends to deal with the problem itself rather than just the effects. It finds ways to change it or avoid it in the future. Problem focus:
- Provides long term solutions to problems
- May not be appropriate in some situations, such as a short term problem that worsens.
- May not work for everyone.
- Different techniques are appropriate for different problems, for example emotion focus can be used with the problem cannot be changed.
- Different techniques suit different people. Some people prefer problem focus compared to emotion focus.
- It is difficult to asses coping styles because answers to questionnaires on coping styles are related to the kind of problem presented.
- Endler and Parker (1990) developed a different scale for measuring coping styles - the Multidimensional Coping Inventory. They found a third coping method style - avoidance-oriented. This involves denying or minimising the seriousness of the situation.
Psychological methods of stress management
Stress Inoculation Therapy (SIT)
Meichenbaum (1985) propesed a therapy to protect an individual before dealing with stress, rather than coping with it. It is a form of cognitive therapy as it aims to change the way we think about a problem.
There are three main stages:
1. Conceptualisation phase - the therapist and client discuss the problem areas.
2. Skills acquisition phase - stress-reduction techniques are taught based on a variety of skills, for example relaxation.
3. Application and follow through - the client practises stress reduction techniques in role play then applies them to real life.
Sheehy and Horan (2004) used SIT with first year undergraduates. After 4 weekly seesions of 90 minutes, the students had lower anxiety levels than a control group and they also performed better academically.
- SIT provides a long lasting method of coping with problems that create stress, and clients learn useful skills.
- It is good for coping with moderate stress but is not as effective for severe stress.
- It is time consuming and requires the clients to be highly motivated.
- Individual differences mean that not all individuals are able to use this method effectively.
Physiological methods of stress management
Drugs - Anaxiolytic drugs that reduce anxiety, for example:
- Benzodiazepines are currently the most commonly used drug. They enhance the effect of the neurotransmitter GABA, the body's natural form of anxiety relief. Gaba reduces activity in the nervous system by slowing transmissions between nerve cells and thus making the person feel calmer. BZ's also reduce seratonin levels, which relate to anger and aggression.
- Betablockers reduce the activity of the sympathetic nervous system, which is critical in arousing the body to deal with a stressor. Therefore, the physical symptoms of stress are reduced. BB's do this by binding onto the receptors of cells in the heart and around the body that usually react to adrenaline.
- Drugs can be effective in reducing stress in the short term.
- They are easy to use and are popular.
- Drugs do not tackle the problem, they only treat the symptoms of the stress and may prevent a person dealing with the problem.
- In the long term, drugs can have some unpleasant side effects and problems of dependance.