Stress

• What is acute stress?

  Immediate stress that triggers the fight or flight response.
• Chronic stress refers to prolonged or repeated stressful situations.
• What is a stressor?


  A stressor is any event or situation that causes stress or triggers a stress response in an individual.
• Hans Selye came up with a theory of a general adaptation syndrome (GAS).
• The GAS has three stages; alarm, resistance and exhaustion
• Alarm stage - the body experiences fight or flight, the body's adrenal glands enlarge and stomach ulcers may develop.
• Resistance stage - the body adapts to the presence of the stressor and alarm stage symptoms disappear. Energy is obtained by burning fats.
• Exhaustion stage - first stage symptoms reappear, there is increased vulnerability to disease and psychological problems.
• Aim of Selye (1936)


  Selye's experiment subjected to rats to different stressors and compared the effects.
• Method of Selye (1936)


  The rats were subjected to stressors such as surgical injury, extremes of temperature, and injections of toxic substances such as formaldehyde. These were repeated over many weeks to prevent recovery.
• Findings from Selye (1936) - The rats showed a physiological triad : enlargement of adrenal glands, bleeding from stomach ulcers and shrinking of lymph tissue.
• Evaluation of Selye (1936) - Selye's study showed a systematic change over time and it kept other variables constant. However, it is hard to generalise the findings from rats to humans. The experiment was highly unethical due to animal cruelty.
• The GAS is a detailed theory of stress, based on experiments looking at bodily changes. However, a lot of the supporting research has been done on animals, making it hard to generalise to humans. Also, the use of very extreme physical stressors in Selye's 1936 study makes it hard to generalise the findings to the stressors we encounter during everyday life.
• Adrenaline is released by the adrenal glands during acute stress. This helps the body to prepare for an immediate threat.
• Cortisol is released during the resistance stage of GAS. It releases energy in a different way - by using up stored energy from fats and muscles. Cortisol is released from the adrenal cortex.
• When the body is aroused by a threat, the sympathetic branch of the autonomic nervous system (ANS) becomes active. These nerves stimulate the adrenal medulla to release adrenaline. Overall, this set of processes is called the SMS. When a threat has passed, the parasympathetic branch of the ANS becomes active, triggers the body to 'rest and digest'.
• Slower response to stress, this involves the hypothalamus in the brain, which instructs the pituitary gland to release a messenger hormone called ACTH, which in turn stimulates the release of cortisol from the adrenal cortex. This set of processes is called the HPA system - bloodstream.
• Short-term health effects of stress include:

  • being more susceptible to infections such as the common cold
  • being moody and irritable
  • having difficulty concentrating
  • finding it hard to sleep
• Long-term health effects of stress include:

  • raised blood pressure (hypertension)
  • increased risk of diseases of adaptation such as coronary heart disease (CHD)
  • slower wound healing
  • skin conditions can worsen
• What is immunosuppression?

  High levels of cortisol in the blood stream can harm the immune system. A key part of the immune system is the lymphatic system which produces white blood cells. If stress is prolonged over several days or more, the production of white blood cells reduces. This makes the body more vulnerable to infection.
• Suzanne Kibosh wanted to know why some workers cope better with stress than others. She believes that some exhibit hardiness, meaning greater psychological resilience. This had three characteristics :

  • commitment : they were highly committed to work and projects
  • control : hardy people had an internal focus of control
  • challenge : they interviewed changes as a challenge rather than a threat.

  These features are called the 3 C's of hardiness.
• Kobasa (1979) gave the SRRS questionnaire to exutives, and found that those with the same score on the questionnaire experienced different levels of illness, depending on their level of hardiness.
• Personality is thought to be relatively stable across the lifespan. Psychologists try to summarise an individual's personality in terms of a small number of traits that can be measured with a personality test.
• A trait called neuroticism is especially relevant to stress. People with high neuroticism are anxious and self-critical, and tend to get stressed about things that other people might not worry about.
• Closely linked to personality is the idea that people's behaviour can be classified into different types. Researchers Friedman and Rosenman (1974) focused on two in particular.
• Type A behaviour : highly competitive and ambitious with a strong desire for recognition and a tendency to rush things.
• Type B behaviour : relaxed, with a lack of ambition or drive and a tendency not to rush or get involved in competitive behaviour.
• Type A behaviour was associated with a higher level of stress and a higher level of heart problems such as CHD. However, neither Type A nor Type B behaviour was originally seen as a personality type, as they may be open to change over the lifespan.
• Sex differences in stress :

  • Women release less adrenaline than men do, and it lasts for less time in the bloodstream.
  • The hormone oxytocin can lower cortisol, an effect which is boosted by oestrogen and reduced by testosterone.
• Age differences in stress :

  • Teenagers are more likely to show the symptoms of stress openly compared to older adults.
  • People of different ages also experience different stressors.
• Aim of Friedman and Rosenman (1974)?


  The researchers aimed to find out whether behaviour patterns could be a risk factor in the health effects of stress.
• Method of Friedman and Rosenman (1974)?


  The researchers used interviews and questionnaires to put people into one of two categories. Over 3000 participants were categorised into types, all of whom were males aged 39-59.
• Findings of Friedman and Rosenman (1974)?

  More than eight years later, the researchers studied health outcomes. 70% of those who had developed CHD had previously been classified as type A.
• Evaluation of Friedman and Rosenman (1974)?

  The study was done on men, and the findings can't easily be generalised to women. It didn't take into account possible interactions between men and their life or work circumstances. Nevertheless, it was a large-scale study, the first to show that psychological factors can impact on heart disease.
• Stressors can be categorised into three main types:

  • social : stress from interactions with other people
  • occupational : stress from our work or studies
  • environmental : stress from our surroundings, such as noise
• Rahe et al. (1970) studied a range of major social stressors using a questionnaire called the social readjustment rating scale (SSRS).
• Rahe et al. found a positive correlation between the number of stressors a person had experienced and their level of ill-health.
• Later researchers have found that miner daily hassles, while smaller in scale, can have a larger cumulative effect on health. Daily hassles are minor but frequent stressors such as loosing your keys or forgetting your lunch.
• Drugs that directly tackle the stress response in the body are frequently prescribed by GPs. Including :

  • Benzodiazapines such as Valium - These boost GABA levels making the person more relaxed.
  • Beta blockers - These block the beta receptors that respond to adrenaline, lowering heart rate and blood pressure.
• Benzodiazapines tend to cause drowsiness. More sever side effects can include confusion, seizures or hallucinations.