We spend about a third of our life asleep and yet very little research has been directed towards solving the main sleep disorder – that of insomnia. Insomnia even lacks a precise definition. Of course insomniacs know what they mean by insomnia – it’s a lack of sleep! And yet if we take such an insomniac into a sleep laboratory for a few nights, the electronic devices that subsequently monitor his sleep will usually show that he sleeps very nearly as much as ‘good sleepers’, as far as his total length of time asleep is concerned anyway.
How come, therefore, that whenever a survey is conducted into sleep it shows that roughly a fifth of the population complains of insomnia? Nobody knows for sure, and perhaps until more research is undertaken on the symptom of sleeplessness our knowledge will remain mainly anecdotal. But if you ask your friends what they mean by insomnia you will get several different answers. Most will say that it is a difficulty in getting to sleep. Others will say it is waking up too early or waking up too frequently in the night, and some will say it is just poor sleep and that they hanker after ‘a really good night’s rest’.
This last attitude is understandable. Sleep gives an opportunity for regeneration and repair of all our tissues, including the brain and muscles. The washed-out feeling after poor sleep is a very real one. During wakefulness, the rate of tissue breakdown in the body exceeds that of repair. In sleep, because of a reduction of energy demands and a different hormone patterning, the rate of renewal exceeds that of tissue breakdown. Experts in sleep, who base their findings on scientific data rather than the symptoms of their patients, are at pains to point out that although insomniacs sleep almost as long as their ‘good sleeper’ controls in the laboratory (and probably at home too), the quality of their sleep is deficient, and so the restorative nature of their sleep is not as good as it should be.
This is no informed guess of the sleep researchers. The electrical brainwaves that can accurately monitor sleep and wakefulness and tot up the sum total of sleep with a high degree of accuracy, show very little difference between the insomniac and the good sleeper. But when other tests are carried out, quite pronounced variations between the bad sleepers and the rest can be measured. The former have higher body temperatures and higher oxygen consumption during the night, and more stress hormones (corticosteroids) circulate through their system.