Stress as a bodily response
‘The non-specific response of the body to any demand’. Stressors; events throw body out of balance. Useful when need to act quickly. Results in arousal; animal react in a situation that threatens survival. Response innate/defensive/adaptive, promotes survival. An assignment, physiologically aroused, motivated concentrate more.
Nervous system; Central Nervous System and the Peripheral Nervous System. CNS: Brain and Spinal Cord. PNS: Somatic Nervous System; voluntary moves and Automatic Nervous System; involuntary moves.
Sympathetic Branch; Activates organs in situations requiring energy and arousal, fight or flight. Shown by increased heart rate, reduce stomach activity, pupil dilation or expansion, relaxed bronchi in lungs. Parasympathetic Branch; storing resources, monitors relaxed state, promotes digestion and metabolism. Decreased heart rate, pupil contraction, constriction of bronchi in lungs.
Endocrine System: number of glands; secrete hormones in to bloodstream which control ANS activity. Homeostasis; normal steady state, placed under stress body gets back to this quickly as poss. Controlled by parasympathetic branch storing energy, sympathetic branch uses when aroused. Need balance between branches.
Sympathetic Adrenal Medullary System
SHOCK: This involves the sympathetic branch SAM.
Stress > Sympathetic > Adrenal Medulla which is part of the Adrenal Glands > releases Adrenaline and Noradrenaline. Sympathetic system aroused, parasympathetic suppressed.Fight or flight response (increase in heart rate, less digestion, increased clotters in case of injury to body etc.).
- Important in the stress response
- It is an appropriate reaction of the body as it prepares us for fight or flight
- SAM activity is not just associated with stress though
- We have more adrenaline and noradrenaline when we are concentrating on a task
- Perception is also important – sometimes we may see heightened activity in SAM as showing we are stressed, at other times it could just show we are excited or stimulated
Pituitary Adrenal System
COUNTER-SHOCK: This involves the parasympathetic branch HPA. Endocrine System produces Corticotrophin Releasing Factor (CRF) stimulates Anterior Pituitary Gland releases Adrenocortitrophic Hormone (ACTH) stimulates Adrenal Cortex releases Glucocorticoids including Cortisol.
Cortisol> coping with long term stress. Cortisol/glucocorticoids conserve glucose for neural tissues, stabilise blood glucose concentration, mobilise protein reserves, conserve salts and water. Reverses stress response> homeostasis. Resources used fast. Anti-inflammatory action of glucocorticoids slow wound healing. Immune system suppressed because of glucocorticoids in the system, meaning we are more prone to illness
- The HPA is of value overall in reducing the negative effects of the initial shock response
- People who do not have adrenal glands, cannot produce normal amounts of glucocorticoids have to be given extra amounts when stressed in order to survive
- There is a cost though with HPA and it cannot continue indefinitely at an elevated level
- If adrenal cortex stops producing glucocorticoids, blood glucose levels not maintained
General Adaption Syndrome
In short term; stress helps cope with environmental demand. Long term; effects may damage
Alarm Reaction; Increased SAM activity, also HPA. 6 – 48 hrs after stress involves both branches. Loss of muscular tone, drop in body temperature. Resistance; Adaptation stage, HPA dominant. Body tries to cope with environment. Parasympathetic uses up body resources increasingly. Increase in adrenal gland activity. Exhaustion; Shock response symptoms reappear; immune system can collapse through damage to adrenal cortex; high blood pressure, asthma more likely.
Evaluation of GAS
- Correctly focused on HPA and the importance of glucocorticoids
- He alerted medicine to the importance of stress in disease, which is commendable
- He didn’t really understand or pay attention to the SAM system or how this links with HPA
- Stress doesn't produce same stress response, different people/emotions affect the response
- Used animals to support research, he overestimated physiological factors at the expense of psychological and cognitive ones
Outline; Daily Hassles
More psychological stress was experienced on days when we experienced hassles than when we did not. DeLongis et al points out major life events occur infrequently, hassles occur dozens of time a year. They formed the hypothesis then that daily hassles would correlate more than life events.
DeLongis et al used a life events scale and their own hassles scale to test which was better. Uplifts were also considered – things that make you feel good in a day like good weather. Participants completed four questionnaires once a month for a year, which were: Hassles scale (117 hassles, such as worries about weight, physical appearance etc), Uplifts scale (135 uplifts, such as recreation, good weather etc), Life events (24 major events) and Health questionnaire.
The frequency and intensity of hassles significantly correlated with impaired health scores on the questionnaire. Daily uplifts had little effect on health though. There was no relationship between life events and health during the study, but there was one for the 2 years before the study.
Evaluate; Daily Hassles
- Original sample consisted of people over 45 – hard to generalise
- Information was obtained only once a month – retrospective so may be unreliable
- Do we know how hassles actually affect us – some evidence that cortisol increases because of hassles
- Life events could actually affect the amount of hassles that people experience too
Overall Evaluation of Hassles
- There is a link between hassles and health
- Can affect training perhaps to help with coping strategies
Kobasa argues people vary in ability to cope with stress . Challenge: have direction in life, Commitment: View stressful situations as a challenge, not a threat, Control: can influence own lives. Hardy people experience less stress, healthier generally. Negative relationship between hardiness and illness. Could also have buffering effect, cope better and so are more resistant to illness.
A pilot study on highly stressed male executives. Those who were didn’t suffer from illness, more likely to be hardy.
Hardiness negatively correlated with stress and physical illness for men and women: similarly, commitment and control negatively correlated but the challenge did not. No buffering effect of hardiness of effects of stress on health for women
Hardiness can be used in training programmes to increase the trait. HardiTraining includes hardiness as a focus, way to improve social support, self care exercises. Several weekly sessions, trainees report back to mentor on successes and failures. Increase job satisfaction, improves health in working adults and decreases blood pressure in workers too.
- Evidence that hardy people do have lower stress and better health than non-hardy people
- Hardiness does buffer the effects of stress on illness, particularly in men
- HardiTraining suggests that hardiness is genuinely important at promoting good psychological and physical health
- Challenge is often irrelevant when combined with commitment and control
- Most research is based on males only – when women are included, the effects of hardiness are more weaker for women than men
- High neuroticism seems to be a large factor in health of individuals, not high hardiness
- Correlational; no cause & effect
Outline; Personality and Stress
Friedman and Rosenman carried out research into effect oh CHD considering Type A: competitive, hostile, restless, pressured, Type B: Opposite to Type A, relaxed and laid back. Longitudinal Study, Self Selected Sample, 3,200 Californian men, All aged between 39 and 59, All healthy to begin with, 8.5 years assessment period, Structured interview & observing. Interviews and observations were used to assess personality type and health status. Assess whether someone was Type A required the interviewer to: Interrupt participants deliberately, look for signs of impatience (like finger tapping) Follow up 8.5 years later; 257 had developed CHD > 70% were type A. Most had been considered workaholics
Type A seems to correlate with CHD. Friedman and Rosenman state that Type A increases experience to stress which increases reactivity, which in turn increases vulnerability. Stress inhibits digestion, leading to higher cholesterol in the blood placing a person at risk of CHD.
Matthews et al reanalysed data from Friedman and Rosenman found hostility aspect of Type A correlated highest with CHD. Ganster et al; elevations of sympathetic system leads to deterioration in cardiovascular system. They put participants in to stressful situations and recorded blood pressure and heart rate. Only hostility from Type A correlated with reactivity. However, lots of psychologists have failed to reproduce such findings, meaning that Type A may not be that important.
Evaluate; Personality and Stress
- Earliest evidence of how illness can be affected by personality
- This study prompted a lot of other research in this area
- It prompted a lot of people to change their lifestyle to lead healthier and longer lives
- Having just 4 categories is dubious
- Type A consists of several aspects, we don’t know which is most important
- Correlational, so cannot establish cause and effect
- It has been difficult to replicate the findings
- Clearly oversimplified to have everyone in the world in one of four categories
- Type A is too broad – hostility seems the most important aspect but this is not certain
- All research is correlational, so we cannot be sure of causation, only a link between the two variables
- The link between Type A and CHD seems to be weakening as time goes on – this could mean Type As are leading healthier lifestyles, or the relationship was never strong in the first place
Johannson et al compared two groups of workers in a sawmill in Sweden. Group 1 – High Risk; repetitive, couldn’t move freely, concentrate continuously. Group 2 – Low Risk Cleaners; far more flexibility, could socialise Urine samples taken: stressful group increased Adrenaline and Noradrenaline higher rates of illness like ulcers and migraines.There was also a higher level of absenteeism among the finishers.
- A strength of this is study is that it has high ecological validity because it was carried out in a real-life setting. Therefore, it is possible to generalise findings.
- There might have been individual differences between the two groups which explain the findings. One group less prone to stress because of personality characteristics.
- It is not possible to conclude which of the stressors induces the most stress.
Burnout; This is characterised by exhaustion, fatigue and weariness from prolonged exposure to stress. It is possible that millions of people are affected by this, especially worrying as it lasts several years. Thought to result in failing HPA and overstimulated SAM, making sufferers prone to CHD.
10,308 civil servants. Aged 35 – 65. 67% male, 33% Female. Longitudinal over.3 years. Job control in particular was measured through a self report questionnaire and evaluating the workplace. Assessed on two occasions 3 years apart. Stress related illness recorded. Correlational analysis carried out between job control and stress related illness.
Low control workers 4x more likely to die of heart attack. More likely to suffer from other stress related illnesses like stomach ulcers, strokes and cancer. Findings consistent on both occasions job control was measured. The association still significant after variables accounted for; employment grade, social support and risk of CHD.
- Self reports are prone to investigator and participant effects.
- Correlations cannot establish cause and effect, nor does this study isolate job control as a variable.
- The jobs of high and low control workers were also very different in other ways than just control – money differences, higher jobs more interesting, more contact etc – these could also have contributed to the results.
Outline; Stress and Life Events
More than one response to stress; nature of the situation can therefore determine the nature of the stress response. Life events are said to cause high levels of stress which require an alteration to be made in a person’s life – a life change, involve changes from homeostasis. Holmes and Rahe believe is because changes involve us absorbing psychic energy, so less available for other things, like fighting off illnesses.
Social Readjustment Rating Scale
Life events make you ill? >Medical Records > Life Events > Rate in order > Results averaged, divided by 10 to create LCUs. The final scale consisted of 43 items, with stress measured by counting up all the events that had been experienced in a one year period. 0 – 149 = low. 150 – 299 = mid. 300+ = high.
2500 US Navy Personnel > SRRS For the last 6 months, rather than the last year > Calculate the LCU score for each person and also record the health records for all sailors > Perform a test of correlation between life changes and illness- +0.118.
Evaluate; Stress and Life Events
Evaluation of Navy Study
- First real study to show a link between life events and illness
- Improvement on previous research as it kept careful records over a 6 month period
- Physical health recorded after life events occurred; likely to be causing the health issues,
- It’s a correlation, so no cause and effect, only weak too at +0.118
- Physical illness can cause life events (consider changes in eating habits for example)
- Biased sample (all American male sailors) – ethnocentric so hard to generalise
- Research in this area was a real breakthrough
- Life events considered serious issue and threat to psychological well-being
- Possible therapeutically to reduce impact of stressful events minimise illnesses
- Research is correlational, so no cause and effect
- It is situation dependent
- Its diverse – positive events don’t have much support
- Retrospective, so unreliable
- Ignores specific effects (depressed = loss events, anxious = danger events)
Stress Inoculation Training
Best known application to stress. Meichenbaum; use such therapy before a person experiences problems rather than afterwards. SIT is a form of coping and stress management. Conceptualisation: Identify source of stress. Skill acquisition; learn specific skills and practice. Application and follow through: try skills in the real world.
There are other ways to assess the success of a technique though, such as measuring cortisol levels. Anotoni et al (2000) found that SIT reduced distress symptoms in HIV positive gay men. Gabb et al (2003) studied the effects of SIT on cortisol levels in healthy people exposed to an acute stressor. The stressor was a job interview followed by an arithmetic task. Half received SIT beforehand. They had lower levels of cortisol and in addition, appraised the situation as less stressful.It is not always the most effective treatment though.Foa et al (1999) assessed it against the prolonged exposure technique for people who had suffered sexual or non-sexual assault resulting in PTSD. Both reduced the PTSD severity and depression. Prolonged exposure also reduced anxiety and social adjustment.
Evaluation of Stress Inoculation Training
- SIT is a form of CBT, and these are regarded as at least as effective as other treatments
- SIT works on short term and long term stress and a variety of stressors
- It works when assessed using self report or by other measures such as cortisol response
- It is valuable to treat people before the problem gets so severe they could develop a disorder
- Unsure which component is most responsible for reducing stress – which is more important, cognitive or behavioural changes?
- SITis often compared against no treatment controls – too easy
- When compared with other treatments, it doesn’t fare as well
- Other factors could be at work here, such as therapist warmth rather than anything specific about SIT
Physiological Stress Management; Beta Blockers
Beta Blockers reduce activity in the sympathetic nervous system. Act directly on heart and circulatory system by decreasing heart rate and lowering peripheral blood pressure. They do not affect the brain in any way.
Beta blockers have been shown to reduce blood pressure and heart disease. Lau et al conducted a meta-analysis and found that they reduce the risk of death by 20% in patients suffering heart disease. Performance anxiety treated using beta blockers. Lockwood found 27% of orchestral musicians used a beta blocker, 19% using every day. Beta blockers are preferred to anti-anxiety drugs as no direct effect on brain and reduce bodily symptoms of stress/anxiety; tremors, sweating palms. Performance quality in musicians has been found to improve with their use. Other studies failed to replicate findings. Performance anxiety related to; social phobia, situations trigger fear. Beta blockers do not help with social phobia
- Drug withdrawal can lead to problems
- Side effects – sleep disturbance, muscle fatigue, gastro-intestinal effect
Physiological Stress Management; Benzodiazepines
Valium/Librium increase activity of neurotransmitter GABA. Reduces serotonin activity, reduces arousal. Effective at reducing anxiety. They are: rapid, effective for majority of people and if used short term, few serious side effects. Side effects; drowsiness, feelings of depression, unnpredictable interactions with alcohol. More likely to be in accidents as less alert. Dependent; rapid withdrawal leading to intense stress and anxiety. Drug escalation; tolerance develops, large doses needed for the same original effect.
Stewart claims long term use can impair visuo-spatial ability. Showed clear deficiencies with cognitive performance improving when Bzs were withdrawn. Buuspirone offers advantages over Bzs; helps effects of serotonin. Davidson studied patients suffering generalised anxiety disorder; treated showed greater improvements than controls. Not as effective as other anti-anxiety drug. No sedative effects, withdrawal symptoms or adverse effects on cognitive functioning.
Very effective at reducing intense stress/anxiety. Don't address problems that causes the stress, best used in conjunction with other treatments; SIT. 4 weeks recommended maximum period of time. Given minimal dose. Dependents should have dose reduced gradually.
Stress and Immune System
Prolonged exposure to stress is claimed to weaken the immune system. Research has been done in this area to prove this. Kiecolt-Glaser et al conducted a study with 75 volunteer medical students. Stress levels were assessed by blood samples taken from the students one month before they were due to sit their final exams, this was the low stress condition, and again at the end of the fist day of their final exams, this was the high stress condition. They analysed the number of T-cells present in both blood samples, these attack foreign bodies in the tissue of the body. In addition to this, participants also had to complete a questionnaire which assessed loneliness, mental difficulties and life events.
It was found that the levels of T-cells were higher in the sample taken a month before the final exams in comparison to the sample take at the end of the first day of final exams. Also, level of T-cells were lower for the participants who were experiencing stressful life events, and where also lower for participants who felt most lonely. From this, it can be concluded that the hormones produced as part of the stress reaction reduce the number of T-cells produced by the body. This, in turn, reduces immune functioning. This study also supports that prolonged exposure to stress weakens the immune system.
Stress and Immune System
- This study is a natural experiment.
- High ecological validity because the stressful situation which was examined was real and natural occurring.
- Easy for the findings to be generalised to other settings.
- Weakness of this study was the sampling procedures. The participants in this study were volunteers, for this reason it is hard to generalise the results.
- The students that did volunteer are likely to be young and educated and therefore may be more compliant.
- In addition to this volunteers may differ in important ways from those who didn’t volunteer.
- A further weakness of this study is that the sample size was very small, only 75, and also there was a higher number of males in comparison to females.
- This is an issue because it makes generalisation to a larger population hard.
Stress and Immune System
Cohen et al also conducted a study into the effect stress has on the immune system. There were 394 healthy participants in this study and their stress levels were assessed by completing a questionnaire designed to measure their stress level. This involved them listing stressful events experienced over the past year, assessing their ability to cope with these events and noted how often they felt negative emotions. Bases on this information, participants were given a ‘psychological stress index’ from 3, low stress, to 12, high stress. Participants were exposed to one of five common cold viruses through nasal drops.
It was found that although most showed signs of infection, only one third were judged by a doctor to have an actual cold. When comparing these results to the stress index given to the participants, a positive correlation was showing, which implies a direct relationship between stress and illness. From these findings we can conclude that the higher the stress index, the more likely the participant is to catch a cold.
Stress and Immune system
- Cohen’s study is most similar to a match pairs experimental design. An advantage of using match pairs design is that individual differences between groups can be controlled.
- The researchers attempted to control the extraneous variables which may have affected the results of this study, they tried to control the factors other than stress which could have contributed to the beginning of a cold.
- The study has a large sample pool and this allows match pairs to be used. This is a strength of the study. However, it can be very difficult to find pairs.
- This study was looking for a direct link between illness and stress, for this reason a correlation was used. Correlations allow a large amount of data to be generated, much more than an experiment, and they also allow predictions to be made.
- Although they can establish causal relationships between illness and stress, cause and effect can not be established.
- Ethics should also be taken into consideration, it is not ethical to infect people with a virus. However, they will have given consent to this.