Apart from God whom the Bible says neither sleeps nor slumbers, all other living creatures do have one time or the other to sleep. Sleep is a condition in which the eyes are closed and the muscles, nervous system etc are relaxed.

Sleep makes it easier for our body to metabolise free radicals-molecules that are said to lead to the ageing of cells and even cause cancer. In a recent study carried out by the University of Chicago, 11 healthy young men were allowed only four hours of sleep a day for six days. At the end of this period, their body cells were performing like those of 60-year-old, and their blood insulin level comparable with that of a diabetes sufferer!

Sleep deprivation even affects the production of white blood cells and the hormone, cortisol, making a person more prone to infectious and circulatory diseases.

Without a doubt, sleep is vital for a healthy body and mind. In the opinion of researcher William Dement, founder of the first Sleep Study Centre, at Stanford University, U.S.A., “sleep seems to be the most important indicator of how long you’ll live.”

Deborah Suchecki, researcher at a sleep study center in Sao Paulo, Brazil, comments: “If people knew what is going on in a sleep-deprived body, they would think twice about concluding that sleep is a waste of time or just for the lazy person.”

Sleep is for the night as work is for the day. While it is easier for the like of teachers, civil servants, and traders for example, to observe their sleep at the perceived normal time -night, others like night guards and nurses on night duties may not.

Sound slumber is essential to retain facts, and sleep seems critical to memory, particularly the ability to recall recently learnt facts and events, researchers have found out.

“We sought to explore whether sleep has any impact on memory consolidation,” said lead researcher Dr. Jeffrey M. Ellenbogen, a post-doctoral fellow at Harvard Medical School’s Center for Sleep and Cognition.

Ellenbogen’s group found that sleep did have a benefit for declarative memory. People in the non­interference groups had mean recall that was slightly higher in the sleep group compared with the wake group. Moreover, people in the interference group who were able to sleep still did significantly better on the recall than did the wake group.

“Sleep had a benefit for the consolidation and strengthening of memory,” Ellenbogen said. The current harsh economic condition in the country, if not for any other thing, has stripped Nigerians of the pleasure of sleep. Many because of the nature of their jobs coupled with the responsibility of meeting family needs do wake up as early as 4:00a.m. to begin the day’s work and sleep as late as 1 a.m.. Others are 24 hours on the internet looking for information.

In the study, published in a 2004 issue of the journal Psychosomatic Medicine, researchers looked at data from 100 adults interviewed for the National Sleep Foundation’s 2001 Sleep in America Poll. The participants were asked how much they slept on a typical workday, whether they had any sleep problems, and how their sleep affected their daily functioning.

Researchers found a U-shaped relationship between the number of sleep problems reported and their total sleep time. In other words, sleep problems were reported more commonly for both short and long sleepers than for those who sleep approximately eight hours.

The study showed sleep problems were common in both long and short sleepers, and women long sleepers than men. Most adults need seven to 10 hours of sleep a night. However, a recent poll by the National Sleep Foundation found 40 per cent of American adults are getting less than seven hours of sleep/night on weekdays. On average, most people are sleeping 6.8 hours per weekday night and 7.4 hours on a weekend night.

Mrs. GA Ariwoola, a vice principal in one of the secondary schools in Ibadan when asked the average hours she used to sleep in a day, said that “by 9:30p.m. I am already in my room ready for the night and by 5:30a.m. I wake up. That is about eight hours. In the afternoon, at times, when the occasion permits, I do rest”.

“Normally, people that have made it have many things to handle. Like politicians, they attend meetings and travel a lot. Wealthy people too don’t rest and that is why they normally have hypertension.”

Miss Opeyemi Ibikunle, a medical student said “I sleep for at least five to six hours in a day. If I don’t sleep very well, 1 do have headache. If a student doesn’t sleep very well or browse over night and go for lectures in the morning, it will affect the level of understanding.”

Dr. O.J. Babalola of Oni & Sons Hospital, Ring Road, Ibadan said “I think six to eight hours is enough on the average for sleep in a day. Sleepless night is part of the price that somebody may have to pay for what he or she has determined to do but it must not be to his or her detriment. When one plans his programme very well, you may not necessary stress your self too much.

“We have positive stress and negative stress. Positive stress is a form of stress you subject yourself to so as to achieve what you want to achieve. That form of stress, we really need it to keep us going. There are some people 24 hours in the laboratory carrying out researches.”

Dr. Victor Makanjuola, Department of Psychiatry, University College Hospital (UCH), Ibadan, said “the number of hours used for sleep defer from individual. Some might have four hours of sleep and it might be adequate while some might require eight hours. On the average, between four to eight hours of sleep should do for a normal adult. Infants sleep for about 16 hours or more in a day. The number of hours you sleep in a day however reduces with age.

“You are more likely to remember things if you read and you sleep. That gives the brain time to organise what you have read. Poor sleep may be one of the symptoms that will herald mental illness. In a way, it is one of the commonest symptoms that you see just before a mental illness is established and it may also occur in an established mental illness. Sleep has a relationship with mental illness.

“If you have a prolonged period of sleep deprivation, then, you are prone to develop some kind of psychiatric disorder-depression, anxiety, and psychoses. In practical terms, we know it aids memory because if you have false sleep, you are less likely to remember things that happened prior to that time than if you have a good sleep.