Zhao Hui/for china daily

Although mental health conditions of the children surveyed vary with age groups, girls between 6 and 11 years appear to emerge with the "most complex problem" profiles.

More than 33 percent of them reported depressive behavior but none sought psychological therapy, except for two girls, who had seen doctors over attention deficit hyperactivity disorder, the report highlights.

The lack of guardianship and familial emotional interactions, and ineffective prevention at home and schools have contributed to the problems, according to Zheng Yi, a pediatrician at the Beijing Anding Hospital of Capital Medical University. Zheng led the research.

"We found that the absence of awareness for mental health problems, and the shortness of mental health service providers to be important factors," Zheng said.

"Besides that, many parents tend to emphasis on physical health over mental health. They ignore the importance of emotional bonding to children's growth. In the face of mental health problems, they have no idea about where to turn and seek help."

According to Zhao, China should have more laws to protect such children, and enhance support systems to provide them psychological care.

Last year, the government brought in a new mental health law that emphasizes on treatment and prevention of disorders. Experts feel the new law offers an opportunity to society to help these lonely children.