Stress: The physiological and psychological state of disruption caused by the presence of an
unanticipated disruptive or stimulating event.
Stressor: Factors or events real or imagined that elicits a stress response
Eustress: stress that adds a positive enhancing dimension to the quality of life
Distress: Stress that diminishes the quality of life commonly associated with disease, maladaption,
illness.
Canon (1914,1932)
- Studied animal’s responses to stressful stimuli
- “fight or flight”
- Under situations of danger, people undergo physiological reactions which prepare the organism
to respond to threat.
Physiological responses to threat
Pupils dilate – see more clearly
Hairs stand up on end – make us seem larger, and making us more sensitive to environment
Heart rate increases and arteries constrict to maximise pressure around the system
The respiratory system open up and breathing speeds up – gets more air in the system so
increased blood flow can be oxygenated. The blood carries oxygen to the muscles allowing them
to work harder.
Fat from fatty cells and glucose from the liver are metabolised – creating instant energy
Blood vessels to the kidney and digestive system constrict – effectively shutting down systems
that are not essential – reduction of saliva in the mouth, bowels and bladder may open up
Blood vessels to the skin constrict reducing any potential blood loss
Sweat glands open up, providing an external cooling liquid
Endorphins are released – reduces pain.
Hypothalamic Pituitary Adrenocortical system (HPA)
1. Corticotropin Releasing factor (CRF) released in response to environmental stressor from
hypothalamus.
2. Adrenocorticotropic hormone (ACTH) is then released by pituitary
3. Which in turn releases cortico –steroids from adrenals.
4. When stressor is terminated – negative feedback occurs, shut down of HPA axis
Seyle’s General Adaption Syndrome
Found rats reaction to new hormones was the same – general stress response
Stage one: Alarm Reaction:
, - Initial dip – lowered immune system –more susceptible to infection and disease
- Trauma causes immediate set of reactions that combat the stress.
- If stress is not severe or long-lasting, we bounce back and recover rapidly.
Stage Two: Resistance:
- Eventually we adapt to stress and become more resistant to illness and disease.
- Our immune systems works overtime for us during this period, trying to keep up with the
demands placed upon it. We become complacent about our situation and assume we can resist
the dangers of stress indefinitely.
Stage Three: Exhaustion:
- Because our body is not able to maintain homeostasis and the long-term resistance needed to
combat stress, we invariable develop a sudden drop in our resistance level.
- Life sustaining mechanisms slow down, organs systems begin to break down and stress-fighting
reserves finally succumb to “diseases of adaptation”
Strengths
General theory variety of stressors
Physiological and environmental interaction
Physiological mechanism for relationship between stress and illness
Weaknesses:
Limited role of psychological factors – individual differences
Assumes responses are uniform
Considers stress as an outcome
Anxiety
Diffuse unpleasant vague sense of apprehension often accompanied by autonomic symptoms
Distinguishable from fear
State Anxiety: experienced at a particular moment increased by an anxiogenic stimulus
Trait Anxiety: Enduring feature of an individual doesn’t vary from moment to moment
DSM identifies 8 subtypes:
1. Panic Disorder
2. Agoraphobia
3. Social phobia
4. Simple phobia
5. OCD
6. PTSD
7. Generalised Anxiety Disorder
8. Unspecified