Causes of Sleep Deprivation

• Shift work

  Hours of paid employment that are outside the period of the normal working day
• Types of shift work

  • Night shifts
  • Early morning shifts
  • Rotating shifts
• Shift work disrupts the natural circadian rhythm
• Circadian rhythm


  The regular, automatic psychological changes that occur during a 24 hour cycle that regulates a person's chemical and hormonal production and metabolism
• Circadian rhythms are affected by the amount of light in a person's environment
• Circadian rhythms

  Operate like an internal body/biological clock that adjusts our physical, mental and behavioural processes
• Circadian rhythms are related to

  The sleep-wake cycle
• Shift work

  Hours of paid employment that are outside the period of the normal working day
• Types of shift work

  • Night shifts
  • Early morning shifts
  • Rotating shifts
• Shift work disrupts the natural circadian rhythm
• Circadian rhythm


  The regular, automatic psychological changes that occur during a 24-hour cycle that regulates a person's chemical and hormonal production and metabolism
• Circadian rhythms are affected by the amount of light in a person's environment
• Circadian rhythms operate like

  An internal body/biological clock that adjusts our physical, mental and behavioural processes
• Circadian rhythms are related to

  The sleep-wake cycle
• People who work the night shift need to be active and alert during the night when melatonin levels are naturally higher
• People who work the night shift need to sleep during the day when melatonin levels are naturally lower
• Shift workers need to override their body’s natural circadian rhythms
• Shift work disorder is an extrinsic circadian phase sleep disorder
• Shift work disorder

  Characterised by insomnia, chronic sleep deprivation and excessive sleepiness when awake
• Shift workers try and sleep during the day causing fragmented sleep
• The person's progression through the sleep stages is disrupted due to fragmented sleep
• Environmental factors affecting shift workers' sleep

  • Higher temperature during the day
  • More natural light during the day
  • More disturbances and activity during the day
• Shift workers do not spend enough time in REM sleep
• REM sleep


  The period in the sleep cycle that restores mental processes
• Shift workers also miss out on NREM sleep
• NREM sleep

  Where the body repairs and regrows tissues, builds bone and muscle and strengthens the immune system
• If this pattern becomes the norm then physiological and psychological functioning becomes impaired
• Examples of shift work

  • Doctors
  • Nurses
  • Jet lag for pilots
  • Flight attendants
• Melatonin


  The hormone that is secreted by the pineal gland that causes drowsiness and helps to regulate the sleep-wake cycle
• Alcohol


  A depressant drug that slows the workings of the nervous system
• Drinking alcohol before bed may help you doze off
• Alcohol disrupts the rhythm of sleep patterns
• You won't feel refreshed in the morning after drinking alcohol
• Other drawbacks of alcohol include waking frequently to go to the toilet
• It is believed that alcohol may provoke fragmented sleep especially in sleep apnea
• Alcohol's effect on muscles

  Alcohol relaxes the muscles of the upper airway
• Relaxation of upper airway muscles


  May lead to a collapse of the airway in susceptible individuals
• Collapse of the airway may result in an arousal from sleep
• This may provoke mixed states of consciousness and lead to an increased risk of sleepwalking
• This has not been validated by testing due to ethical concerns and confounding variables