Sleep deprivation

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Sleep deprivation is a general lack of the necessary amount of sleep. This may occur as a result of sleep disorders, active choice or deliberate inducement such as in interrogation or for torture.

[edit] Uses

[edit] Scientific study

In science, sleep deprivation (of rodents, e.g.) is used in order to study the function(s) of sleep and the biological mechanisms underlying the effects of sleep deprivation. Sleep deprivation, can result in a form of psychosis if sleep is deprivated for more than 5 days, however, sleep deprivation cannot kill a human.^{[citation needed]}

Some sleep deprivation techniques are as follows:

• gentle handling (often require polysomnography): during the sleep deprivation period, the animal and its polygraph record are continuously observed; when the animal displays sleep electrophysiological signals or assumes a sleep posture, it is given objects to play with and activated by acoustic and if necessary tactile stimuli.^[1] Although subjective,^[2] this technique is used for total sleep deprivation as well as REM or NREM sleep deprivation.

This mouse is being deprived of restful REM sleep by an animal researcher using a single platform ("flower pot") technique. The water is within 1 cm of the small flower pot bottom platform where the mouse sits. At the onset of REM sleep, the exhausted mouse would either fall into the deep water only to clamber back to its pot to avoid death from drowning, or its nose would become submerged into the water shocking it back to an awakened state.

• single platform: probably one of the first scientific methods (see Jouvet, 1964 for cats^[3] and for rodents). During the sleep deprivation period, the animal is placed on an inverted flower pot whose bottom diameter is small relative to the animal size (usually 7 cm for adult rats); the pot is placed in a large tub filled with water to within 1 cm of the flower pot bottom. The animal is able to rest on the pot and is even able to get NREM sleep. But at the onset of REM sleep, with its ensuing muscular relaxation, it would either fall into the water and clamber back to its pot or would get its nose wet enough to waken it. So this technique is used only for REM sleep deprivation.
• multiple platform: in order to reduce the elevated stress response induced by the single platform method,^[4] developed this technique in which the animal is placed into a large tank containing multiple platforms, thus eliminating the movement restriction experienced in the single platform. This technique is also used only for REM sleep deprivation.
• modified multiple platform: modification of the multiple platform method where several animals together get the sleep deprivation (Nunes and Tufik, 1994).
• pendulum: animals are prevented from entering into PS by allowing them to sleep for only brief periods of time. This is accomplished by an apparatus which moves the animals' cages backwards and forwards like a pendulum. At the extremes of the motion postural imbalance is produced in the animals forcing them to walk downwards to the other side of their cages.^[5]

[edit] Torture

Sleep deprivation can be used as a means of torture. Under one interrogation technique, a subject might be kept awake for several days and when finally allowed to fall asleep, suddenly awakened and questioned. Menachem Begin, the Prime Minister of Israel from 1977-83, described his experience of sleep deprivation when a prisoner of the KGB in Russia as follows:

In the head of the interrogated prisoner, a haze begins to form. His spirit is wearied to death, his legs are unsteady, and he has one sole desire: to sleep...Anyone who has experienced this desire knows that not even hunger and thirst are comparable with it.^{[citation needed]}

In 2006, Australian Federal Attorney-General Philip Ruddock argued that sleep deprivation does not constitute torture. ^[6] In rats, prolonged, complete sleep deprivation increases both food intake and energy expenditure, leading to weight loss and, ultimately, death.^[7] Nicole Bieske, a spokeswoman for Amnesty International Australia, has stated, "At the very least, sleep deprivation is cruel, inhumane and degrading. If used for prolonged periods of time it is torture."^[8]

[edit] 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 ^[9]. Many tricyclic antidepressants happen to suppress REM sleep, providing additional evidence for a link between mood and sleep ^[10]. Similarly, tranylcypromine has been shown to completely suppress REM sleep at adequate doses.

[edit] Voluntary

Sleep deprivation has sometimes been self-imposed to achieve personal notoriety in the context of record-breaking stunts. One such record belonged to Randy Gardner, who stayed awake for 264 hours (eleven days). Lt. Cmdr. John J. Ross of the US Navy Medical Neuropsychiatric Research Unit later published an account of this event, which became well known among sleep-deprivation researchers.

[edit] Causes and treatments

[edit] School

A National Sleep Foundation survey found that college/university-aged students get an average of 6.8 hours of sleep each night.^[11] Sleep deprivation is common in college freshmen as they adjust to the stress and social activities of college life. A study performed by the Department of Psychology at the National Chung Cheng University in Taiwan concluded that freshmen received the shortest amount of sleep during the week.^[12]. Students get more sleep each night in the summer than during the school year,^{[citation needed]} and one in four U.S. high school students admit to falling asleep in class at least once a week.^[13]. Research has indicated that teenage children have a variation in their circadian cycle that delays sleep past the normal time for adults. Since school schedules are based around the adult workday, it is not surprising that students have difficulty obtaining adequate sleep.^{[citation needed]} In 1997 the University of Minnesota did research that compared students who went to school at 7:15 a.m. and those who went to school at 8:40 a.m. They found that students who went to school at 8:40 got higher grades and more sleep on the weekdays. ^[14]

[edit] Longest period without sleep

Depending on how sleep is defined, there are several people who can claim the record for having gone the longest without sleep:

1. Thai Ngoc, born 1942, claimed in 2006 to have been awake for 33 years or 11,700 nights, according to Vietnamese news organization Thanh Nien. It was said that Ngoc acquired the ability to go without sleep after a bout of fever in 1973,^[15] but other reports indicate he stopped sleeping in 1976 with no known trigger.^[16] At the time of the Thanh Nien report, Ngoc suffered from no apparent ill effect (other than a minor decline in liver function), was mentally sound and could carry 100 kg of pig feed down a 4 km road,^[15] but another report indicates that he was healthy before the sleepless episode but that now he was not feeling well because of the lack of sleep.^[16]
2. In January 2005, the RIA Novosti published an article about Fyodor Nesterchuk from the Ukrainian town of Kamen-Kashirsky who claimed to have not slept in more than 20 years. Local doctor Fyodor Koshel, chief of the Lutsk city health department, claimed to have examined him extensively and failed to make him sleep. Koshel also said however that Nesterchuck did not suffer any of the normally deleterious effects of sleep deprivation.^[17] People who claim not to sleep are usually shown to sleep when studied in sleep laboratories with EEG. Nesterchuck reports experiencing drowsiness at night, commenting that he attempts to sleep "in vain" when he notices his eyelids drooping. Many people experience microsleep episodes during sleep deprivation, in which they sleep for periods of seconds to fractions of a second and frequently don't remember these episodes. Because microsleep is frequently not remembered, microsleep or a related phenomenon may be responsible for lack of sleep and/or lack of memory of sleep in individuals like Nesterchuk and Thai Ngoc.
3. The Guinness Book of World Records in its 1978 edition stated that "The longest recorded period for which a person has voluntarily gone without sleep is 449 hr (14 days 13 hours) by Mrs. Maureen Weston of Peterborough, Cambridgeshire in a rocking chair marathon on 14 Apr.-2 May 1977." The Guinness Book of Records has, however, withdrawn its backing of a sleep deprivation class because of the associated health risks.
4. A 3-year-old boy named Rhett Lamb^[18] of St. Petersburg Florida has a rare condition and has only slept for one to two hours per day in the past three years. He has a rare abnormality called an Arnold-Chiari malformation where brain tissue protrudes into the spinal canal. The skull puts pressure on the protruding part of the brain. It is not yet known if the brain malformation is directly related to his sleep deprivation.

[edit] See also

• Fatigue
• Insomnia
• Microsleep
• Narcolepsy
• Polyphasic sleep
• Randy Gardner - sleep deprivation record holder
• Sleep debt
• Sleep medicine
• Sleep onset latency
• Touch the Truck

[edit] References

[edit] Further reading

• National Sleep Foundation 2005 Sleep in America Poll
• Sleep deprivation effects on the activity of the hypothalamic spituitary adrenal and growth axes: potential clinical implications, by Alexandros N. Vgontzas, George Mastorakos, Edward O. Bixler, Anthony Kales, Philip W. Gold & George P. Chrousos

[edit] External links

• Brain activity is visibly altered following sleep deprivation
• "How Much Sleep Do You Really Need?", U.S. National Sleep Foundation