Sleep deprivation

From Wikipedia, the free encyclopedia

Sleep deprivation is a general lack of the necessary amount of sleep. A person can be deprived of sleep by their own body and mind, as a consequence of some sleep disorders, or, actively, by another individual. Sleep deprivation is sometimes used as an instrument of interrogation. It has been reported that sleep deprivation affects tens of millions of adults each year.<ref name="SleepDepAdult">"http://library.cqpress.com/cqresearcher/ppv.php?id=cqresrre1998062600".</ref>

It very rarely results directly in deaths of healthy humans, though it can lead to accidents or injuries leading to death.<ref name="SleepDep">"http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Sleep_deprivation?OpenDocument".</ref>

1 Effects of Sleep Deprivation
2 As a cause of diabetes
3 Effects on the brain
4 Effects on growth
5 Impairment of ability
6 As a cause of obesity
7 As a form of torture
8 As a treatment for depression
9 Sleep deprivation and school
10 Prevention of effects in soldiers
11 Microsleep
12 See also
13 References
14 External links

[edit] Effects of Sleep Deprivation

Lack of sleep may result in<ref name="SleepDep">"http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Sleep_deprivation?OpenDocument".</ref><ref name="SleepDep2">"http://www.apa.org/ed/topss/bryanread.html".</ref><ref name="SleepDepLuc">"http://www.lucidnet.co.uk/sleep/disorders/deprivation.htm".</ref><ref name="SleepDep4">"http://www.postgradmed.com/issues/2002/10_02/pn_sleep.htm".</ref><ref name="SleepDep8">"http://www.vineland.org/mennies/sleep_trouble_in_school.htm".</ref><ref name="SleepDepHarvard">"http://www.health.harvard.edu/press_releases/sleep_deprivation_problem.htm".</ref><ref name="SleepDepJiskha">"http://www.jiskha.com/health/social_health/sleep_deprivation.html".</ref><ref name="Fiedu">"http://www.fi.edu/brain/sleep.htm".</ref>:

irritability
blurred vision
slurred speech
memory lapses / memory Loss
overall confusion
hallucinations
hernia
Erectile dysfunction
nausea
psychosis
depression
decreased mental activity
decreased concentration
Decreased ability for the immune system to fight off sickness
Weight gain
increased blood pressure
Aching muscles
Faster aging
Impatience
Slowed reaction time
Misbehavior
Yawning
Daytime Naps
Hypertension/Hyperactivity
dizziness

[edit] As a cause of diabetes

A 1999 study by the University of Chicago Medical Center shows that sleep deprivation severely affects the human body's ability to metabolize glucose, which can lead to early-stage Diabetes Type 2.<ref name="DGottlieb">"Daniel J. Gottlieb, et al. Association of Sleep Time With Diabetes Mellitus and Impaired Glucose Tolerance. Arch Intern Med. Vol. 165 No. 8 2005; 165: 863-867 PMID 15851636.".</ref>

[edit] Effects on the brain

Sleep deprivation can adversely affect brain function.<ref name="Fiedu">"http://www.fi.edu/brain/sleep.htm".</ref>A 2000 study by the UCSD School of Medicine and the Veterans Affairs Healthcare System in San Diego, used functional magnetic resonance imaging (fMRI) technology to monitor activity in the brains of sleep-deprived subjects performing simple verbal learning tasks.<ref name="BrainStudy">"http://health.ucsd.edu/news/2000_02_09_Sleep.html".</ref> The study showed that regions of the brain's prefrontal cortex (PFC) displayed more activity in sleepier subjects. Depending on the task at hand, in some cases the brain attempts to compensate for the adverse effects caused by lack of sleep. The temporal lobe, which is a brain region involved in language processing, was activated during verbal learning in rested subjects but not in sleep deprived subjects. The parietal lobe, not activated in rested subjects during the verbal exercise, was more active when the subjects were deprived of sleep. Although memory performance was less efficient with sleep deprivation, greater activity in the parietal region was associated with better memory.

The British television reality show Shattered aired in 2004, in which contestants had to endure seven days with very little sleep. The effects of sleep deprivation on the brain were captured on 24/7 cameras.

[edit] Effects on growth

This section is a stub. You can help by expanding it.

According to a 1999 study<ref name="BlockQuote">"Alexandros N. Vgontzas, George Mastorakos, Edward O. Bixler, Anthony Kales, Philip W. Gold & George P. Chrousos, published in Clinical Endocrinology, Volume 51 Issue 2 Page 205, August 1999".</ref>:

Sleep deprivation results in a significant reduction of cortisol secretion the next day and this reduction appears to be, to a large extent, driven by the increase of slow wave sleep during the recovery night. Deep sleep has an inhibitory effect on the HPA [Hypothalmic-pituatary] axis while it enhances the activity of the GH [growth hormone] axis. In contrast, sleep disturbance has a stimulatory effect on the HPA axis and a suppressive effect on the GH axis. These results are consistent with the observed hypocortisolism in idiopathic hypersomnia and HPA axis relative activation in chronic insomnia. Finally, our findings support previous hypotheses about the restitution and immunoenhancement role of slow wave (deep) sleep.

[edit] Impairment of ability

According to a 2000 study published in the British scientific journal, researchers in Australia and New Zealand reported that sleep deprivation can have some of the same hazardous effects as being drunk.<ref name="Drunkhazard">"http://oem.bmjjournals.com/cgi/content/abstract/57/10/649".</ref><ref name="Drunkhazard2">"http://oem.bmjjournals.com/ Occupational and Environmental Medicine".</ref> Getting less than 6 hours a night can affect coordination, judgment and reaction time. People who drove after being awake for 17–19 hours performed worse than those with a blood alcohol level of .05 percent, which is the legal limit for drunk driving in most western European countries (the U.S. set their blood alcohol limits at .08 percent). In addition, as a result on continuous muscular activity without proper rest time, effects such as cramping are much more frequent in sleep-deprived individuals. Extreme cases of sleep deprivation have been reported to be associated with hernias, muscle fascia tears, and other such problems commonly associated with physical overexertion. Beyond impaired motor skills, people who get too little sleep may have higher levels of stress, anxiety and depression, and may take unnecessary risks. According to the National Highway Traffic Safety Administration, over 100,000 traffic accidents each year are caused by fatigue and drowsiness.<ref name="SleepDepReport">"http://www.apa.org/monitor/oct01/sleepteen.html".</ref><ref name="HolyName">"http://www.holyname.org/healthcare/excellence/njnsleep/sleep_deprivation.htm".</ref> A new study has shown that while total sleep deprivation for one night caused many errors, the errors were not significant until after the second night of total sleep deprivation<ref>Journal of Sleep Research "Effects of two nights sleep deprivation and two nights recovery sleep on response inhibition".</ref>

[edit] As a cause of obesity

A 2005 large study of a nationally representative sample of about 10,000 adults, suggested that the U.S.'s obesity epidemic might have as one of its causes a corresponding decrease in the average number of hours that Americans are sleeping.<ref name=Bristol>Does the lack of sleep make you fat?, Bristol University Press Release, December 7 2004</ref> The study suggests that this might be happening because sleep deprivation might be disrupting hormones that regulate appetite. The study found that people between the ages of 32 and 49 who sleep less than 7 hours a night are significantly more likely to be obese. Other scientists hold that the physical discomfort of obesity and related problems, such as sleep apnea, reduce an individual's chances of getting a good night's sleep.

[edit] As a form of torture

This section is a stub. You can help by expanding it.

Sleep deprivation is considered by some to be torture. It has been used as a way of interrogating suspected terrorists.<ref name="SleepTorture">"http://www.smh.com.au/news/National/Sleep-deprivation-is-torture-Amnesty/2006/10/03/1159641317450.html".</ref> Interrogation victims are kept awake for several days, then when they are finally allowed to fall asleep, suddenly awakened and questioned. However, this is a controversial issue.<ref name="SleepTorture2">"http://www.abc.net.au/pm/content/2006/s1754821.htm".</ref><ref name="SleepTorture3">"http://au.news.yahoo.com/061003/21/10rum.html".</ref> Nicole Bieske, a spokeswoman for Amnesty International Australia, has stated, "At the very least it [sleep deprivation] is cruel, inhumane and degrading. If used for prolonged periods of time it is torture."<ref name="SleepTorture">"http://www.smh.com.au/news/National/Sleep-deprivation-is-torture-Amnesty/2006/10/03/1159641317450.html".</ref>

[edit] As a treatment for depression

Recent studies show sleep deprivation has some potential in the treatment of depression. About 60% of patients, when sleep-deprived, show immediate recovery, with most relapsing the following night. The incidence of relapse can be decreased by combining sleep deprivation with medication <ref name="Ncbi">"http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10459393&dopt=Abstract".</ref>. Incidentally, many tricyclic antidepressants happen to suppress REM sleep, providing additional evidence for a link between mood and sleep <ref name="SleepDepEmedicinehealth">"http://www.emedicinehealth.com/articles/42677-5.asp".</ref>

[edit] Sleep deprivation and school

In the United States sleep deprivation is common with students due to the fact that almost all schools begin early in the morning, forcing students to get less sleep than they normally would.<ref name="SleepDepSchool">"http://sleepdisorders.about.com/cs/sleepdeprivation/a/backtoschool.htm".</ref> Because of this, their grades go down and their concentration is impaired, and students, who should be getting between 8.5 and 9.25 hours of sleep, are getting only 7 hours due to the strict school policies.<ref name="SleepDepSchool">"http://sleepdisorders.about.com/cs/sleepdeprivation/a/backtoschool.htm".</ref> In several school districts, the opening of school was delayed by over an hour to give students more sleep. For example, in 1997 the University of Minnesota did research that compared students who went to school at 7:15 and those went to school at 8:40. They found that students that went to school at 8:40 got higher grades and more sleep on the weekdays.<ref name="SleepDepReport">"http://www.apa.org/monitor/oct01/sleepteen.html".</ref><ref name="SleepDepRep">"http://www.nysut.org/research/bulletins/981202adolescentsleep.html".</ref> The National Sleep Foundation did a survey and found that students get an average of 6.8 hours of sleep, which is far below the amount needed.<ref name="SleepDepAb">"http://sleepdisorders.about.com/cs/sleepdeprivation/a/depstudents.htm".</ref> Students get more sleep in the summer than during the school year.<ref name="SleepDepSummer">"http://www.healthysleeping.com/focus_article.asp?f=sleep_disorders&c=sleep_backtoschool&b=healthysleeping&spg=SHO".</ref> It is reported that one in four students doze off in school.<ref name="SleepDepAbcNews">"http://abcnews.go.com/US/wireStory?id=1775003".</ref>

[edit] Prevention of effects in soldiers

Since sleep deprivation is a fact of modern combat, the U.S. Army, through DARPA, has a "Preventing Sleep Deprivation Program", which has the goal to prevent the harmful effects of sleep deprivation and provide methods for recovery of function with particular emphasis on cognitive and psychomotor impairments. Their efforts include new pharmaceuticals that enhance neural transmission, nutraceuticals that promote neurogenesis, cognitive training, and devices such as transcranial magnetic stimulation.

The United States military has recently begun to explore the use of a new drug called modafinil, which has prevented the negative effects of sleep deprivation in soldiers. Modafinil may increase wakefulness through activation of noradrenergic and dopaminergic systems, possibly through interaction with the hypocretin/orexin system PMID 15532213.

[edit] Microsleep

A microsleep is a period of sleep lasting no more than a few seconds up to a minute, and often occurs as a result of a sleep debt, sleep deprivation, or mental fatigue.<ref name="Micro1">"http://www.sleepdex.org/microsleep.htm".</ref> Microsleeps (or microsleep episodes) become extremely dangerous when occurring during situations which demand continual alertness, such as driving a motor vehicle or working with heavy machinery. People who experience microsleeps usually remain unaware of them, instead believing themselves to have been awake the whole time, or feeling a sensation of 'spacing out'.<ref name="Micro2">"Ogilvie RD. The process of falling asleep. Sleep Med Rev 5: 247-270, 2001 (PMID 12530990)".</ref><ref name="Micro3">"PMID 14592362".</ref><ref name="Micro4">"PMID 15320529".</ref>

There is little agreement on how best to identify microsleep episodes. Some experts define microsleep according to behavioral criteria (head nods, drooping eyelids, etc.), while others rely on EEG markers, which are known to be weakly correlated with the behavioral features of sleep.^{[citation needed]}