US scientists find, sleep pattern controls mental health condition in children. Children suffering from insomnia and hypersomnia are severely depressed when compared to their peers with normal sleep.

Sleep-disturbed children, with both insomnia and hypersomnia were more likely to face severe depression than those with either insomnia or hypersomnia.

In the study led by Xianchen Liu, MD, PhD, and colleagues of the University of Pittsburgh, 553 children with a depressive disorder were observed. Almost three quarters of these children reported to have sleep disturbance, 53.5 percent had only insomnia, 9 percent had hypersomnia alone and 10.1 percent had both these disturbances.

Children with both insomnia and hypersomnia reported a longer history of illness, were more severely affected and likely to have weight loss, fatigue, and other problems, compared with those with either insomnia or hypersomnia.

Depressed girls report more sleep disturbance than boys.

"We know that depression is associated with sleep problems. But what this study shows is that, in depressed youths, not all sleep problems are the same," Liu said in a prepared statement.

"Insomnia is the most common problem, but having a combination of insomnia and sleepiness is 'double trouble'."

Experts recommend 10-11 hours of sleep for grammar school-aged children and 11-13 hours for pre-school children every night.