A 10-year-old girl who recently suffered headaches, vomiting and listlessness was diagnosed with sibling rivalry disorder after doctors found that her parents were focusing their attention on her infant brother born six months ago.

Second Hospital Affiliated with the School of Medicine at Zhejiang University, where the girl was taken for assistance, said she is one of a small number of children received this year who has been diagnosed with the emotional disorder after being forced to share attention from their parents.

The issue is gaining prominence as families have ushered in a second child. The universal second-child policy took effect at the beginning of this year.

"The number of such cases is rising," said Feng Jianhua, director of pediatrics at the hospital.

After the girl was examined, doctors excluded the possibility of encephalitis, which can cause some of the symptoms she experienced. She had an outgoing personality and was a class monitor at a school in Huzhou city. The experts finally found that the root cause of the problem was the arrival of a newborn in her family.

"We found that the parents spent almost all their time with the baby and only talked about the younger child when chatting with their friends. The girl felt neglected," Feng said.

Doctors and psychologists said the problem lies with the parents, who need to show equal love and care for all their children.

"When children are accustomed to a one-child environment, some will feel pressure with the coming of a brother or sister who will share everything, including parents' love. Parents should help them develop a sense of responsibility and love toward the younger child, beginning when the mother becomes pregnant," said Xun Yan, a Beijing-based independent psychologist.

Parents should also be aware of feelings and avoid comparing two children. They should also not force the elder child to share toys or snacks with the younger one if they don't want to, Feng said.