Sleep deprivation is the general term given to describe a state that occurs due to an inadequate amount of sleep or a consistent low quality of sleep. Sleep is as vital to the human body as food or water, and an insufficient amount of sleep can have severe effects on both physical and mental health. Disruptions to the sleep cycle and circadian rhythms such as shift work or jet lag have consequences on how the body functions.
A person who is sleep deprived is more likely to have impaired judgment, is accident prone and make decisions that could affect them negatively. An individual who has not slept for more than 24 hours have a severe lack of hand eye coordination and suffers from similar symptoms of a person who has a blood alcohol level of 0.1. Sleep deprivation is not only linked to physical health, but also to mental health and the way we perform daily tasks.
Sleep deprivation can occur due to multiple reasons. The most common reason for sleep deprivation is personal choice. Many people chose to go to bed at a late hour after spending time socialising or watching television, causing a reduce in the amount of sleep they get. Another reason is illness, as something such as tonsillitis can keep a person awake due to pain they are experiencing and they sleep poorly. Other reasons include sleep disorders such as insomnia or sleep apnoea, a poor sleeping environment or shift work.
The topic of sleep deprivation on health related to psychological principles through altered states of awareness, or often known as altered states of consciousness. Consciousness is the term given to a process by which the brain creates a model of internal and external experience. Altered state of awareness is the term that describes a state where thoughts and actions that differs from that of a normal conscious person. Sensory overload, sleep deprivation and trauma can all lead to an altered state of awareness. A study conducted at Harvard University uncovered that a sleep deprived brain can not be in control of its sensorimotor functions and can have long term negative affects.
Circadian Rhythms are mental, physical and behavioral changes that follow a 24-hour to 25-hour cycle, responding mainly to the light and darkness in the environment. Circadian Rhythms are found in most living things such as animals, humans, plants and even tiny microbes. The study of Circadian Rhythms is called Chronobiology. The body has more than 100 circadian rhythms. Each unique 24-hour cycle influences an aspect of your body’s function, including body temperature, hormone levels, heart rate, blood pressure and even pain threshold. Scientists can’t explain how this helps your brain ‘keep time’ but they do know the brain relies on outside influences known as zeitgebers, to keep it on a 24-hour schedule.
Exogenous Rhythms are regulated by external events in the environment. Endogenous Rhythms are internally driven.
External Factors associated with Circadian Rhythms:
- Daylight – when daylight hits your eyes, cells in the retinas signal your brain
- Social Contact
- Regular Meal Times
- All of these things send time keeping messages to your brain.
Sleep hygiene refers to habits and practices that are conductive to sleeping well on a regular basis and can be introduced through different situations such as a repetitive sleep wake cycle. You sleep better when your temperature is lowest, which is commonly in the early hours of the morning between 4 and 6am. You’re most likely to wake up when your temperature starts to rise, between 6am and 8am. As you age, your brains ‘pacemaker’ looses cells which changes your circadian rhythms – mainly noticeable in how you sleep.
There are 5 stages of sleep. The first 4 stages of sleep are non REM (Rapid Eye movement). The fifth and final stage of sleep is REM (Rapid Eye Movement). Each cycle last approximately 90 minutes, and each person experiences roughly 4-6 cycles per night. The first time through the cycle you only spend about 10 minutes in REM Sleep – which increases to 30 to 60 minutes by the last cycle. When a person suffers from sleep deprivation, they do not experience each stage of sleep and therefore do not get the benefits they would such as waking up feeling refreshed.
There are both long term and short term effects that occur when a person does not get an adequate amount of sleep both with chronic sleep deprivation and partial sleep deprivation. Chronic sleep deprivation is where a person does not get enough sleep over an extended period of time, and suffer from the effects long term. Partial sleep deprivation is the term given to a person who has some sleep during a 24-hour period but not enough to meet needs, and may only occur occasionally. In cases of extreme sleep deprivation, psychosis can occur, where a person experiences being desensitized to surroundings and at a loss of personal identity. They struggle to cope with people and the environment, however this usually only occurs after 6 days of sleep deprivation.
The most common short term effects of sleep deprivation include anxiety, drowsiness, becoming easily distracted, a decreased alertness and cognitive impairment and severe stress. These symptoms occur as the sleepiness a person feels slows down their thought processes, putting them in an altered state of awareness. Concentration levels are lowered and it becomes more difficult to complete complex tasks. The nerve connections that make our memories are strengthened during sleep, and therefore sleep deprivation causes stress and forgetfulness. Without sleep, anything learned or experienced over the day will not be embedded in short term memory. In addition to these short term affects that severely alter an individuals state of consciousness, long term effects are even more dangerous. People who suffer from chronic sleep deprivation are more likely to experience anxiety disorders and depression. They are also at a higher risk of chronic health problems such as high blood pressure, heart disease and stroke. The interruption of circadian rhythms can lead to these problems and severely affect a persons mental health and physical well being.