How deadly is sleep deprivation?

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How Deadly is Sleep Deprivation?
Emilie Wlodaver

As I sit in front of the computer among this sea of studying women, I can’t help but wonder what kind of damage I am doing to myself and that these other women are doing to themselves from days of irregular sleeping interspersed with days of no sleeping.  It is notorious that college students are sleep deprived especially at this time of year when everyone is struggling to finish their work and cram for those final exams.  The conversations in the computer lab are all the same: “Oh yeah, I only have a 300 page paper on how to make a peanut butter and jelly sandwich and a final exam in the meaning of life left.”  So what does sleep deprivation do to the brain and body?  I know that I have a headache of the most extreme dimension and it feels like someone has been sitting on my back and I can feel my fingers starting to tingle and my stomach is grumbling but I’m in such a trance of concentration that I can’t bring myself to go get something to eat.  Someone help me!  I guess I only have three more days left until I can sleep a full eight hours, so it’s all good.  I just have to be a trooper for these last few days.

So back to the original question: how bad is sleep deprivation for you anyway?  First of all, sleep deprivation affects about 47 million American adults which is equivalent to about the quarter of the population (1).  That means that there is a very good chance that the people who are in charge of some of the most important jobs or activities are sleep deprived like the neurosurgeon who is about to perform a transorbital lobotomy on your favorite cousin.  He’s probably sleep deprived.  This is a problem because sleep deprivation can interfere with memory, energy levels, mental abilities, emotional mood, coordination, reaction time, and judgment.  And to top it all off, sleep deprivation can also alter your body’s ability to metabolize glucose which can eventually lead to symptoms similar to early stage diabetes.  The effects of sleep deprivation sound a lot like being drunk.  And actually, a study conducted in Australia and New Zealand suggested that sleep deprivation can have some of the same effects as being drunk (2).  It has been estimated that about 100,000 road accidents per year are directly related to sleep deprivation (5).

What causes sleep deprivation and what are the medical consequences?  There are a number of sleep disorders that often go undiagnosed due to the high frequency of sleep deprivation in the population and the lack of awareness of the adverse effects.  Some of these sleep disorders include insomnia, sleep apnea, restless leg syndrome, and narcolepsy (3).  Some issues that everyone faces that can also cause sleep deprivation include not allowing enough time for sleep, excessive worry/stress/excitement, depression, repeated awakenings from noise, working at night, traveling across time zones, food activities such as caffeine, and some medical conditions (4).

It’s easy to tell when you are sleep deprived because you just don’t feel on point.  What isn’t so clear to the outside world is what exactly is going on within the brain and the body.  First of all, it’s important to understand what purpose sleeping actually serves.  Unfortunately, the exact purpose of sleep is still somewhat of a mystery although there have been major advances in the research of sleep thus producing several theories.  Some of these theories include the adaptive theory which says that sleep improves an animals’ likelihood of survival if its sleeping patterns are appropriate to the environment that they live in.  Another theory is the energy conservation theory which states that animals with fast metabolisms sleep more than those with slow metabolisms and are thus able to conserve their energy.  The restorative theory, which seems to be very popular, states that the body restores itself during sleep.  Researches have found some evidence for this restorative property of sleep.  They have found that cells divide, tissue is synthesized, and growth hormones are released during sleep.  Another study performed at the University of California, San Francisco found that cats that had recently experienced an environmental challenge and were then allowed to sleep for six hours after the stimulation developed twice the amount of new brain connections than cats that were kept awake.  This evidence demonstrates that sleep has implications in the plasticity of neurons.  These brain connections appear to occur mostly in stages of deep sleep and consequently, babies and young animals spend up to half of their sleep time in deep sleep (8).   The programming-reprogramming theory suggests that important information is sent to memory whereas information that is useless is erased from memory.  

Sleep is characterized by five stages (four of which are non-REM and one REM) which can be identified by using electroencephalogram (EEG) measurements to record the activity in the brain.  There are four EEG rhythms that can be found in the brain: alpha, beta, delta, and theta rhythms (9).  It is hypothesized that non-REM and REM sleep both serve different purposes but are equally important.  In a night of sleep, a person will cycle through these five stages.  The first cycle may last around 100 minutes.  The subsequent cycles last longer.  If a person gets a full night of sleep, they are likely to complete a total of 5 cycles (10).  The sequence of sleep states is regulated by nuclei in the brainstem, mostly located in the pons and basal forebrain.  The pons appears to be responsible for regulating REM sleep since people with lesions in the area of the brain have reduced or non-existent REM sleep (11).  In turn, the pons will send signals to the thalamus and the cerebral cortex, which is responsible for thought processes.  During REM sleep, motor neurons in the spinal cord are also turned off creating a momentary paralysis.  Other sleep phases are characterized by certain groups of nerve cells releasing neurochemicals that assist in the relay of information from one neuron to another.

Now that it is understood that sleeping is not just a momentary coma in which nothing is going on (in fact a lot of brain activity is going on during sleep), it can better be understood that lack of sleep can alter the benefits that are acquired during a restful and restorative night of sleep.  There is no doubt that an adequate amount of sleep is crucial to proper brain functioning.  In a 2000 study performed by the University of California, San Diego School of Medicine, it was observed that during certain tasks, the brain will try to compensate for the detrimental affects of sleep deprivation.  Using fMRI techniques, they found that sleep deprived subjects displayed more activity in the prefrontal cortex.  However, when performing tests requiring verbal learning, sleep deprived subjects did not show any activity in the temporal lobe whereas rested subjects did show activity in this language processing region of the brain.  Contrastingly, the sleep deprived subjects showed increased activity in the parietal lobes during the verbal exercise yet still had diminished memory capabilities (7).  Not only does sleep deprivation affect the brain, it also affects all physiological functioning in the body.  Several studies have been performed that suggest that sleep deprivation can increase the risk for cancer, heart disease, diabetes, and obesity (12).  These increased risks could be due to an alteration in hormone regulation due to lack of sleep.  What scientists suggest is that sleep deprivation puts the body in a state of high alert thus increasing the levels of stress hormone that can lead to all sorts of heart diseases.  It has also been suggested that melatonin, a hormone released during sleep, is protective against the growth of certain cancer causing tumors.  Therefore, people who do not produce enough melatonin due to lack of sleep may be more at risk for cancer.  

As I sit here finishing up my work, I wonder to myself if any of the words that I am typing are actually making any sense.  I suppose my I-function is in hyperactive mode trying to compensate for how my body functions normally when I am well rested.  I can only hope that it’ll hold out for a few more days.  What I have learned is that there is no doubt that sleep is crucial to productivity.  Yet, in a society in which there are more and more things that need to be tended to, there is less and less time to rest.  Can careless mistakes be overcome by just a few more hours of sleep?

   
      WWW Sources
1)    http://www.sleep-deprivation.com/; Sleep Deprivation. The causes, effects, and dangers of sleep deprivation on the Sleep Deprivation website
2)    http://archives.cnn.com/2000/HEALTH/09/20/sleep.deprivation/; CNN.com. Sleep deprivation as bad as alcohol impairment, study suggests
3)    http://www.ninds.nih.gov/disorders/brain_basics/understanding_sleep.htm; National Institute of Neurological Disorders and Stroke. Brain basics: Understanding sleep
4)    http://www.cdc.gov/nasd/docs/d000701-d000800/d000705/d000705.html; NASD. Sleep deprivation: Causes and consequences
5)    http://www.apa.org/monitor/oct01/sleepteen.html; Monitor on Psychology. Sleep deprivation may be undermining teen health
6)    http://www.webmd.com/news/20000209/lack-of-sleep-takes-toll-on-brain-power; WebMD. Lack of sleep takes a toll on brain power
7)    http://health.ucsd.edu/news/2000_02_09_Sleep.html; University of California, San Diego Medical Center News Release. Brain activity is visibly altered following sleep deprivation
8)    http://www.fi.edu/brain/sleep.htm; The Franklin Institute Online: The Human Brain. Renew- Sleep and stress
9)    http://bioweb.usc.edu/courses/2003-spring/documents/bisc230-lab_sleep.pdf; What is sleep?
10)    http://www.sleepdisorderchannel.com/stages/; Sleep Channel. Sleep stages
11)    http://www.sfn.org/index.cfm?pagename=brainBriefings_rEMSleep; Society for Neuroscience. REM sleep
12)    http://www.washingtonpost.com/wp-dyn/content/article/2005/10/08/AR2005100801405.html; Washingtonpost.com. Scientists finding out what losing sleep does to a body

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