MELBOURNE: Sleep could be a key player in reducing the impact of attention deficit hyperactivity disorder (ADHD), an Australian study published on Wednesday has found.

The research, compiled by the Murdoch Childrens Research Institute (MCRI), found that the symptoms of ADHD were exacerbated in 70 percent of children with the disorder who struggle to sleep.

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

Mulraney said that 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," she said.

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

"Researchers will now undertake a trial of 300 children to establish if programs developed by psychologists and pediatricians can change sleep habits of children and alter their behavior.

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

"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 optimistic that solving sleep problems can change quality of life for the better by altering behavior, academic achievement and ADHD symptoms.