It's 11am, and 18-month-old Chloe is sleeping soundly in her father's arms. Father and daughter are the envy of passing parents, battling with noisy, demanding toddlers. But this scene of tranquillity is deceptive. Chloe kept her parents up most of the night, as usual. Every evening for the last year, she has woken up half a dozen times, and it's almost impossible to get her back to sleep.
After more than a year of this disturbance, Chloe's parents are besides themselves from lack of sleep. So much so, that the couple have been referred to a sleep centre for therapy, after their baby was diagnosed as suffering from night waking and settling problems.
According to research presented to a Royal College of Psychiatrists conference at the weekend, as many as a quarter of all children aged under five now have severe sleep problems, which means that they are difficult to get to sleep and that they wake up at least three times a night.
Night waking and settling problems are not only the seeds of potential long-term behavioural problems in the child; they are also a source of anxiety, stress and depression in the rest of the family.
There's also growing evidence that many fraught and despairing parents are getting prescription drugs for children as young as nine months, to help them to go to sleep so that the whole family can get some rest.
We all need sleep; an adult requires an average of seven and half to eight hours, every night. In contrast, a newborn baby will sleep most of the time, waking once every three hours, while a six-month child should be able to sleep most of the night, apart from waking in the early morning for a drink. By nine months, the baby should have established a routine, and at 12 months ought to be sleeping without waking for 10 to 12 hours a night.
But, as Dr Paul Ramchandani and his team say in their research at Oxford, one in four children does not have a sleep routine, and the problem in most cases is that they have never been taught. Sleep is a learnt behaviour, and many parents fail to teach it properly. That failure can lead to years of problems, because once a child has found that he or she can get attention by crying, whatever the time of day or night, the rot has set in.
"Sleep problems are very common in under-fives, but 12 per cent of 12- year-olds also have settling and waking problems, and among those with learning disabilities, it can be as high as 50 to 60 per cent," says Dr Lyn Quine, a reader in health psychology at Kent University.
The rates are also higher among children who suffer from nocturnal asthma, eczema and chronic illnesses, as well as a range of rare disorders involving defects of the central nervous system. These symptoms can affect the rest of the family, triggering sleep deprivation, anxiety and depression.
It can also effect physical health and performance. "Sleep is essential for our physical and emotional well-being. It can, for example, seriously undermine the functioning of the immune system, making us vulnerable to infection," says Professor William Regelson of Virginia University, co-author of The Melatonin Miracle.
Researchers in San Diego have gone some way to proving the point, by depriving a group of men of sleep between 3am and 7am on one night, the most common period for night waking. They found that the levels of the body's natural defences against viral infections had fallen significantly when they were measured the following morning.
In the past, many families have muddled through …