Melbourne, Jul 12 (IANS): Sleep could be a key player in reducing the impact of attention deficit hyperactivity disorder (ADHD), a study published on Wednesday has found.

The research, compiled by the Murdoch Children's Research Institute (MCRI), found that the symptoms of ADHD were exacerbated in 70 per cent of children who have the disorder and struggle to sleep, Xinhua news agency reports.

Making "simple adjustments to the bedtime routines of children with ADHD" could make a significant difference, said lead researcher Melisssa Mulraney.

She said the research indicated that children with ADHD who had consistent routines were less anxious at bedtime and found it easier to sleep.

"The children that had the good habits were less likely to argue around bedtime, they slept for longer overall, and they were more alert and less sleepy during the day," the report quoted Mulraney as saying.

"Even if you are not sleeping well, even without ADHD you are not concentrating and paying attention," she added.

Researchers will undertake a trial of 300 children to establish if the programmes developed by psychologists and paediatricians can change the sleep habits of children and alter their behaviour.

Mulraney said, "Our body clock, our circadian rhythm that makes us feel sleepy, is influenced by external cues like daylight, temperatures and timing of meals."

"If you have a set routine: brush your teeth and then read a book, then the body starts to get used to that routine and you start to feel more sleepy simply by going through the routine."

Mulraney said she is hopeful that solving sleep problems can change quality of life for the better for the children with the disorder by altering behaviour, academic achievement and ADHD symptoms.