What is sleep?

Whatever it is, we do quite a lot of it. Newly born babies can sleep as many as eighteen hours a day. This slowly tapers off so that, by the age of four years, children sleep between ten and twelve hours. During their early years in school you should expect them to sleep about nine hours. Then experience suggests that, as you grow older, you settle into a pattern of sleeping between seven and eight hours a night. Some believe that the need for sleep actually decreases as you advance into old age, but there is no scientific evidence of this. Once the sleep pattern is established, it seems to carry through the rest of your life unless something interferes with it.

So what exactly is sleep?

The simple answers to the question are that sleep is the time we rest, or the time when we are not awake. But such answers are unhelpful when we know that lack of sleep can have serious consequences (bearing in mind that sleep deprivation is used as an interrogation technique or, in extreme cases, as torture). Modern research now offers some explanations of the physical processes involved, but there is still uncertainty as to why we need sleep. This creates very real problems for the pharmaceutical companies in designing medications to help people sleep. Until we understand what sleep is for, it may be dangerous for a drug simply to produce unconsciousness because that is not sleep, i.e. it does not allow the body and mind to go through the physiological and psychological functions of the natural sleep cycle. You should note that, as a modern drug, Ambien works by reducing brain activity, allowing people to relax into a more natural sleep.

The sleep cycle

There is a natural cycle that varies between sleep characterised by the presence or absence of Rapid Eye Movement (REM). The change takes place roughly every one hundred minutes with approximately three-quarters of total sleep in adults being without REM. In this more common state, the body remains physically active while the brain becomes relatively inactive with little dreaming. As you fall asleep, your body progresses through four separate stages of non-REM sleep starting with "light" and moving through to "deep" sleep. These phases can only be detected by using an electroencephalogram (EEG). In REM sleep, the eyes can be seen moving rapidly under the lids and the body hardly moves at all. This is the time we are most likely to dream.

Why do we sleep?

Researchers speculate that while we sleep, we physically repair ourselves. This includes the usual housekeeping of cell replacement and tissue regeneration, to the more serious functions of repairing a wound or recovering from an illness or disease. There are also probable functions related to memory. Our cognitive abilities to analyse situations and make reasonably rational decisions depend on having our memories sorted into different categories. Where memories are grouped and stored will depend on whether the outcomes were good or bad for us. We also produce different compounds and hormones that help us to grow and rejuvenate, balance our energy needs and maintain our moods. Whatever the detail, it is clear that we need sleep so that we can maintain our health and function at or near our best.

How does cognitive behavioural therapy help? One of the best alternatives to simple reliance on a drug like Ambien is cognitive behavioural therapy (CBT). CBT teaches you a new set of behaviours around the "activity" of sleep. You have to "relearn" the association between going to bed and falling sleep.

The habit of sleep Before you start taking Ambien or alongside a course of Ambien, you should change your habit patterns and practise relaxation techniques to help you get to sleep.