Pathophysiology

• Complex interaction of specific characteristics related to the person and their environment - psychological, biological, social
  • Genetic factors may include a biological vulnerability to inherit a fearful disposition
  • Behavioural factors include acquisition of fear through classical conditioning and maintenance through operant conditioning
  • Cognitive factors influence attentional biases and selective attention

The stress response

• Exposure to stress results in instantaneous and concurrent biological responses
  • To assess the danger
  • To organise an appropriate response
• Amygdala acts as the emotional filter of the brain for assessing whether sensory material via the thalamus requires a stress or fear response
• This is modified by later-received cortically processed signals
• There are a series of responses to the stressor prior to the point at which stimulation of the adrenal gland causes the release of cortisol
• Acute stress leads to dose-dependent increase in catecholamines and cortisol
• Cortisol acts to mediate the stress response - through negative feedback it acts on the pituitary, hypothalamus, hippocampus and amygdala
  • These sites are responsible for the stimulation of cortisol release, therefore acute stress increases cortisol levels

Clinical features

Physical symptoms

• Sweating, hot flushes or cold chills
• Trembling or shaking
• Muscle tension or aches and pains
• Numbness or tingling sensations
• Feeling dizzy, unsteady, faint or lightheaded
• Dry mouth (not due to medication or dehydration)
• Feeling of choking
• A sensation of a lump in the throat, or difficulty in swallowing
• Difficulty breathing