Sleep: a wake-up
Hyperactivity, even ADHD, may be caused by late nights, says Tessa Thomas

Most children feel a little ratty after a poor night’s sleep. But some sleep experts now suggest that sleep deprivation is actually the cause of many forms of hyperactivity, including ADHD.

“Sleep problems have always been recognized as a symptom of ADHD, but they are as likely to be a cause,” says Dr Stephen Sheldon, director of sleep medicine at the Children’s Memorial Hospital in Chicago and author of Paediatric Sleep Medicine, a medical textbook.

“It has long been observed that children have a paradoxical reaction to stimulants and are effectively sedated by them, which is why a stimulant like methylphenidate (Ritalin) is used to calm them down.” But, he says, it is actually the symptoms that are paradoxical: “Children become hyperactive rather than sleepy when they are severely sleep-deprived.”

If he is right – and there is a growing body of opinion to support his view – then Ritalin works for an overtired child much as a jug of coffee works for an underperforming office worker: their behaviour improves in response to stimulation.

It’s not just ADHD that is misinterpreted as a behavioural rather than a sleep problem, says Dr Luci Wiggs, research fellow at the Oxford University child and adolescent psychiatry unit. This is evident among children who would not be clinically labelled as disruptive. “Children appear to be getting less sleep overall, and we’re seeing a major effect on their learning, thinking, behaviour, relationships and susceptibility to accidents that can be labelled as hyperactive,” she says.

Research has indicated that just and hour’s extra sleep can have a big impact on children’s behaviour. Dr Avi Sadeh, a psychologist at Tel Aviv University, compared a group of 9 to 11-year-olds who had slept for an hour longer than usual with those who had an hour less than usual. When he tested the children after five nights on this new regime, he found that the extra-sleepers scored much higher for memory, recognition and reaction.

As he explains: “There are good reasons to believe that with the nightly temptations such as television and computers in their bedrooms, many children are chronically sleep-deprived – and it shows in their behaviour.” The fact that none of these children had difficulty falling asleep an hour earlier than usual was equally telling.

We are too ready to blame children’s behaviour on a medical condition, suggests Professor Lyn Quine, a health psychologist at Kent University and author of Solving Children’s Sleep Problems. She has worked with children with physical and behavioural problems and says: “You can readily judge the existence of a sleep problem from the child’s daytime behaviour. If it is disruptive, parents need to address the sleep issue first because over activity and poor concentration are often signs of tiredness.”

Quine says there is inadequate training in sleep problems for frontline health professionals, and even when they recognize sleep deprivation in a child they are ill equipped to give practical advice. “Meanwhile, the child’s disruptive daytime behaviour and lack of sleep feed off each other and parents get caught in a vicious circle.”

Quine takes a dim view of the widespread prescription of Ritalin (about 25,000 children in Britain take the medication, with the number rising). “It’s terrible that children are tagged with a medical condition before the simple behavioural solutions for what might be simple sleep deprivation have been contemplated.”

Many parents are now aware just how much sleep their children require or how badly a deficit can affect their behaviour, according to Mandy Gurney , a sleep therapist and co-founder of Millpond Sleep Clinic, a specialist children’s sleep service.

“They think babies are sleeping the whole time and of that need rapidly declining, especially between the toddler and school years. But a four-year-old needs on average only two hours less than a two-year-old,” says Gurney, who this week appears in a BBC documentary about sleep.

It is the shift of daytime to nighttime sleep that really changes as they grow. So a one-year-old will take 2.5 hours out of is 14-hour quota in the day, while a five-year-old will just have 11.5 hours at night. Minorities of children do appear to need less sleep, but in most cases their performance improves with more.

It is not always lack of parental knowledge that causes children to sleep badly. About 10 per cent of children have their sleep interrupted by snoring and 3 per cent by sleep apnoea (where the airways are temporarily blocked). Night-time breathing problems are increasingly caused by obesity, but more commonly by enlarged tonsils or adenoids.

Significantly, a study at the University of Louisville found that a quarter of five to seven-year-olds diagnosed with mild ADHD also had mild sleep apnoea in the night. Once the night-time breathing difficulties were treated, usually with surgery, their behaviour improved.

The Times, 1 February 2005