DEFINITION OF STRESS
When an event or person (stressor) causes someone to change biologically and/or psychologically; this change is due to our 'fight or flight' instincts. The response may make people feel unable to cope.
A stressor is an event or person that triggers a person to become biologically or psychologically stressed. It could be a positive or a negative event e.g. a positive event would be winning the lottery, a negative event would be a family death.
Biological reactions include: shaking, increased heartrate, dry mouth and dilated pupils.
Psychological reactions include: anxiety, irriatability, anger.
Environmental factors could be: divorce, deadlines, births, deaths. weddings.
The autonomic nervous system (ANS) becomes active when we are stressed. It is made up of two parts: the sympathetic branch (activated during stress) and the parasympathetic brance (reduces symptoms of stress).
BODY'S RESPONSE TO ACUTE STRESS (short term response): Sympathomedullary Pathway:
- Hypothalamus in the brain sends signals
- Sympathetic branch of ANS is aroused (pupils dilate, etc)
- Triggers the adrenal medulla- part of the adrenal glands, above the kidneys
- This releases the hormones adrenaline and noradrenaline into the blood, maintaining the fight or flight response
Bodily Responses cont.
BODY'S RESPONSE TO CHRONIC STRESS (long term response): Pituitary Adrenal System:
- Hypothalamus (in the brain) sends signals to the pituitary gland (within but not part of the brain)
- This secretes Adrenocorticotropic hormone (ACTH)
- Stimulates adrenal cortex
- Produces corticosteroid hormones e.g. cortisol
- This enables the body to maintain steady supplies of blood sugar
SEYLE'S GENERAL ADAPTATION SYNDROME (GAS): Experimented on rats, injecting them daily. Rats showed distress injection. After several months, they showed several physiological symptoms, including stomach ulcers. The content of the injection was irrelevant. The stress they experienced was prolonged, leading to more serious problems than a temporary stressful event.
- It is 'general' because it is the same response to all agents
- The term 'adaptation' is used because it is adaptive- the healthiest way for the body to cope with extreme stress.
- It is a 'syndrome' because there were several symptoms in the stress response.
Seyle's GAS model
STAGE 1: Alarm: Threat of stress is recognised and 'alarm' begins. The hypothalamus activates the sympathetic branch of the ANS which triggers the adrenal medulla to produce adrenaline and noradrenaline leading to fight or flight e.g. increased heart rate, sweaty palms, etc.
STAGE 2: Resistance: All alarm systems are at full capacity, so the parasympathetic nervous system (PNS) calls for more cautious use of resources. The body is adapting to the demands of the environment but at the same time, resources are gradually being depleted.
STAGE 3: Exhaustion: Eventually the body's systems can no longer maintain normal functioning. At this point, the initial symptoms may reappear (sweating, etc). The immune system may not be able to cope because production of necessary proteins has been slowed in favour of other needs. This may result in stress related illnesses such as ulcers, depression, cardiovascular problems and other mental and physical illnesses.
- (+) Helps us understand need to reduce stress to avoid severe consequences
- (-) Ignores individual differences and individual's coping mechanisms
- (-) Not all stressors produce the same pattern of physiological activity
- (-) Mainly worked on rats, difficult to generalise as we have different genetics/coping strategies
STRESS AND THE IMMUNE SYSTEM (acute stress)
Stress reduces the immune system's ability to deal with antigens such as viruses (immuno suppressive effect). The body produces more corticosteroids e.g. cortisol. Continuous production affects leucocyte activity and antibody activity and antibody production. Decreasing production of B cells and T cells.
Kiecolt-Glazer et al- Acute Stress: Carried out a natural experiment investigating whether short term stressors (exams) had an effect on the immune systems of medical students. Blood samples were taken one month before (low stress) and during the exam itself (high stress). Immune system functioning was assessed by measuring Natural Killer cell activity in the blood samples. Activity was significantly reduced in the second sample, suggesting that short term, predictable stressors reduce immune system functioning, increasing vulnerability to illness.
- (-) Sample bias- can't be generalised beyond medical students
- (-) Individual differences- some students could have had unknown life changes or daily hassels
- (-) Ethical issues- pps should be in good health with no illnesses or infections before the blood samples were taken.
Stress and the Immune System cont. (Chronic)
Kiecolt-Glaser et al (chronic stress): Used a matched pairs design. Participants were recruited using newspaper adverts. 2 groups: carers and non-carers. Both groups had 13 women matched on age (47-81) and income, but not marital status. Pps given a 10-item perceived stress scale to check how stressed they actually did feel. A measure of immune response was taken (assessed levels of cytokines). All pps given a wound (punch biopsy) which is a cut of 3.5mm below the elbow. Carers indicated they were more stressed on the perceived stress scale, their cytokine levels were lower and it took longer for the wound to heal (9 days). Stress supresses the immune system and therefore wounds take longer to heal.
- (+) Important implications for treating people with infections, particularly those recovering from surgery. Important to reduce stress as much as possible to speed up recovery.
- (-) Matching of pps was inexact e.g. more carers were married and were non-smokers.
- (-) Only 13 pps in each condition, hard to generalise results.
- (-) Pps should be in good health and no illness/infections prior to the study.
Holmes & Rahe: from their work in hospital, they noticed many patients, particularly those with heart disease reported significant life events in the year before they become stressed. hey found that a life event was a change in life circumstances which required a degree of adjustment. To rate the impact of different events, they asked 394 people to compare 43 life events with marriage in terms of the degree of adjustment necessary. Marriage was given an arbitary value of 500 and other events were scored higher or lower. Final scored were divided by 100 and referred to as LCUs (Life change units). The scale was called the SRRS (Social Readjustment Rating Scale). If a person has less that 150 LCUs they have a 30% chance of suffering stress. 150-299- 50% chance. Over 300 LCUs- 80% chance of suffering stress.
- (+) Generated a wealth of research into link between life events and stress. First research to attempt to quantify levels of stress in people's lives.
- (+) Importent implications- shows that life events can lead to ill-health
- (-) Culture bias, carried out in US, can't be generalised
- (-) Retrospective, can be unreliable
Life changes cont.
Rahe et al: Investigated correlation between number of life events and illness. Used approx. 2700 male naval personnel as they embarked on a tour of duty (about 7 months). The men filled in a questionnaire assessing the number of life events experiences in the previous six months and their illness record was assessed over the period of their duty. Each man was given an illness score and a LCU score and these were correlated. There was a positive correlation of 0.118, this is relatively low but still significant. A relationship was found to exist between life events and illness, and the link is likely stress however other factors must be involved due to low correlation.
- (-) Gender and culture bias, male, US navy, hard to generalise
- (-) Correlational study, correlation doesn't imply causality, only association, can't establish c&e
- (-) Unreliable data- possible men didn't recall events accurately
- (-) Is SRRS a valid measure. Reductionist- focuses on life events rather than chronic stressors
DeLongis et al: Disagreed with the concept of the SRRS and major life changing event. They believed that the biggest source of stress was the load of day-to-day troubles e.g. losing keys. They felt these could be eased by the effect of 'uplifts'- little daily boosts e.g. receiving a compliment. They wanted to see if daily hassles were a better predictor of ill health.
100 pps completed 4 questionnaires every month for a year: Hassle scale, Uplifts scale, Life events questionnaire and Health questionnaire.
They found daily hassles correlated with ill health, but uplifts and life events weren't. They concluded daily hassles were more likely to cause stress related illnesses than life events.
- (+) Measure of daily hassles is a better predictor of day-to-day health than measuring LCUs
- (-) Correlational. Cause and effect can't be established.
- (-) Retrospective memories
WORKPLACE STRESS (CONTROL)
Marmot et al- The Whitehall study: Investigated the job strain model which proposed that the workplace creates stress and illness in two ways: high workload and low job control e.g. deadlines, procedures, etc. They predicted higher grade employees would experience high workload strain and low grade workers would experience low job control.
7372 civil servants answered questionnaires on workload, control and social support. They were checked initially for signs of CVD (cardiovascular disorder). They were reassessed five years later. Found workers with less control were four times more likely to die of heart attack than their collegues with more control; also more likely to suffer from other stress related illnesses e.g. cancers, ulcers, stomach disorders and strokes. Concluded that lack of control seemed to be associated with illness, recommending employers gave their staff more independence and contol.
- (-) Correlational
- (-) Self report technique- possibly figure out what researcher wants and answer bias
- (-) Unmeasured factors may have contributed e.g. lower grade workers may share a characteristic that makes them vulnerable to heart disease that wasn't measured.
- (-) Biased, all civil servants
Workplace stress cont (WORKLOAD)
Johansson et al: investigated effects of performing repetitive jobs which require continuous attention and some responsibility. Compared workers in a Swedish sawmill (high risk group) with maintenance workers (low risk group). High risk workers had stressful jobs, repetitive task with an unrelenting pace and sense of responsibility for everyone; because if they fall behind, everyone's production slows. The low risk group had less monotonous jobs and more flexibility.
High risk group was found to have higher illness rates and higher levels of adrenaline in their urine. Also had higher hormone levels on work days than rest days. Evidence of a direct link between job demand, stress hormones and illness.
- (+) Valuable findings, suggesting higher job demand causes stress related illness- we need to reduce job demand in order to reduce workplace stress.
- (+) Measure of stress hormones in urine is an objective measure of stress levels, reducing the chance of investigator effects- higher validity that self report techniques. (
- (-) Natural experiment using correlational data
- (-) Individual differences not taken into account- personality type may have been a factor
STRESS AND PERSONALITY
Generally lives at a higher stress level. Driven by:
- Enjoyment of achieving goals
- Highly competitive
- Hate failure
Generally lives at a lower stress level and typically:
- Work steadily but don't become stressed
- When faced with competition, they don't mind losing
Stress and Personality cont.
Friedman & Rosenman: Investigated link between Type A personality and increased risk of CHD. 3200 Californian men between ages 39 and 59. All pps free from any sign of CHD. Longitudinal study over 81/2 years. Structured interview and observation, assessed personality type and health status. Personality type was determined by amount of impatience, competitiveness and hostility reported and observed during interview. Pps were classified as A1 (Type A), A2 (Not fully type A), X (Equal amounts of Type A and B) or B (Fully B).
Followed up 8yrs later and incidence of CHD recorded. 7% (257 pps) had developed signs of CHD, 70% of these had type A personality. Type A's found to have higher levels of cholesterol, adrenaline and noradrenaline than Type B's. Produced higher levels of fatty acids in the blood. All which may lead to atherosclerosis. Research shows Type A behaviour pattern strongly linked with CHD.
- (-) Biased sample- gender, age, culture
- (+/-) Lacked internal validity- unclear which aspect of Type A was most strongly associated with CHD.
Stress and Personality cont. 2
Shekelle et al: Studied over 1200 male pps with Type A behaviour. Assessed them by self report questionnaire and structured interview. Found over 7 years that there was no difference in the incidents of heart disease between the Type A and Type B groups.
- (-) Sample biased- males.
- (+/-) Self report techniques
Kobasa: Hardy personalities are resisitant to stress. He believes you needed the 3 C's. Control: internal locus of control- feel they are in control of their lives. Commitment: get involved in things, have a sense of purpose. Challenge: see life as a challenge rather than a threat, enjoy a challenge. All 3 C's result in less bodily responses to potential stressors- suffering less stress related illness.
- (+) Reseach supported by Lifton et al- university students who were high in hardiness far more likely to complete their courses.
- (-) Correlational. Can't say not having a hardy personality causes stress related illness.
- (-) Research based upon self-report questionnaires- biased, social desirability and retrospective
PSYCHOLOGICAL STRESS MANAGEMENT
Psychological: focus on the stressful situation and help person cope with situation through Cognitive Behavioural Therapy (CBT): Stress Inoculation Training and Hardiness Training.
Michenbaum- Stress Inoculation Training: Believed we can change the way we think about stressors by changing negative thoughts into positive ones- to cope better in future. 1) Conceptualisation Phase- Therapist and client establish relationship and identify sources of stress in lives. Client is educated about the nature and impact of stress. Encouraged to keep a diary of stressful experiences. 2) Skills Acquisition Phase- Coping skills are taught and practiced primarily at the clinic. Skills taught are tailored to client's own problems. Includes: positive thinking, relaxation, social skills, methods of diversion, time management and social support. 3) Application Phase and Follow Up- Encouraged to use coping skills in real world. Various techniques used: imagery, modelling and role playing. May even be asked to help train others.
(+) Very flexible-wide variety of cognitive and behavioural techniques tailored to client's stressors (+) Successful in dealing with stress of chronic pain, performance anxiety, word related stress (Michenbaum), helping athletes deal with stress of competition (Mace, Eastmen & Cartoll) and patients prepare for surgey (Langer, Janis & Wolfer)
Psychological Stress Management cont.
Michenbaum evaluation cont: (+) Trains client relaxation techniques giving them somecontrol over any stressful situation. (-) Takes time, commitment and money
Kobasa's Hardiness Training:
- 1) Focusing- taught to identify physical signs of stress e.g. muscle tension and identify sources of stress.
- 2) Reliving Stress Encounters- therapist helps person go back over stressful situation and analyses how they coped to gain insight into coping skills.
- 3) Self-improvement- learn new techniques to improve ability to cope. Focus on seeing stressors as a challenge and taking control of situations rather than problems to escape from.
(+) Deals with problem rather than symptoms- teaches client to manage all stressors in life. (+) Studies have shown effecttiveness of hardiness training in improving health and performance in working adults and students (Maddi et al) (-) Involves time, commitment and money- not appropriate for everybody.
BIOLOGICAL STRESS MANAGEMENT
BENZODIAZEPHINES (BZs): Have become the most commonly prescribed drugs used to treat stress and anxiety disorders. They slow down the activity of the central nervous system. BZs increase the activity of the neurotransmitter GABA which is the body's natural form of anxiety relief whose role is to reduce the activiity of other neurotransmitters throughout the brain and so make the person feel more relaxed. The reduced activity of serotonin and noradrenaline seems to be particularly important in reducing the feelings of stress and anxiety.
BETABLOCKERS (BBs): All act directly on the heart and circulatory system to reduce sympathetic arousal. The role of BBs then is to reduce the activation of the cardiovascular system (heart and blood vessels). They do this by binding to cells of the heart and other parts of the body that are normally stimulated during arousal and so block chances of them being stimulated. This had the effect of reducing the activity of adrenaline and noradrenaline, decreasing heart rate and lowering blood pressure. The person is left feeling calmer and less anxious. Beta blockers are sometimes used by sportsmen and musicians to reduce the negative effect of sympathetic arousal on their performance.
Evaluation of Biological Stress Management
- (+) Effectiveness: Kahn et al followed nearly 250 patients over 8weeks and found that BZs were significantly superior to a placebo. A meta-analysis of studies focusing on the treatment of social anxiety found that BZs were often more effective at reducing this anxiety than other drugs. Beta-blockers have been found to significantly reduce the symptoms of anxiety that can hinder some musicians playing, In a study of over 2000 musicians in an American symphony orchestra, 27% of musicians reported taking beta blockers. These people said they felt better about their playing and their performances were judged to be better.
- (+) Ease of use (practicality): Saves time, effort and money compared to something such as stress-inoculation. By reducing heart rate and blood pressure so rapidly, BBs can have a life saving effect in people with life threatening hypertension.
- (-) Addiction: Major problem with BZs is they lead to physical independence. Patients taking even a low dose show withdrawl symptoms. Recommended use for only short time.
- (-) Side effects: BZs have range of side effects including tiredness, memory impairment, increased aggressiveness and sedation. As BBs aren't interfering with brain activity they are not associated with any severe side effects.
- (-) Treats symptoms, not cause: As soon as treatment stops, symptoms often reappear because drugs don't target source of problem- only temporary bandage- not always appropriate particularly if treatment produces further problems (addiction).