About 61 million children in China are classified as 'left-behind' by their parents, who have moved away for work. Although most live with relatives and have adequate provisions, the psychological toll can be enormous and can result in anti-social behavior, poor academic perfomance and even suicide.

Boarders have a PE class at the primary school of Shicheng Township of Pingshun County, north China's Shanxi province, May 26, 2015. The children in the school are mostly left behind children whose parents work outside of their hometown. [Photo/Xinhua]

More than 15 percent of "left-behind" children have no physical contact with their parents during the course of a calendar year,and 4 percent receive just one phone call a year, according to a survey released on Thursday morning.

Data from a survey conducted by an NGO called Shangxuelushang, or "On the Way to School".

The plight of these children was highlighted on June 9, when four siblings in Bijie, Guizhou province, committed suicide by drinking pesticide at home.

The children had not seen their father since March, when he left home to work in Guangdong province. Their mother left the family home in March last year after a fight with her husband that left her hospitalized.

The survey, conducted by an NGO called Shangxuelushang, or "On the Way to School", found that a large number of children are left at home, and their parents have failed to assume their roles as legal guardians. Many parents either lose all contact with their children or fail to communicate with them effectively.

Data from a survey conducted by an NGO called Shangxuelushang, or "On the Way to School".

Data from a survey conducted by an NGO called Shangxuelushang, or "On the Way to School".

"The results defy imagination. Many parents do not even know that it's necessary to communicate with their children on a regular basis," said Liu Xinyu, who led the survey team.

Between October and December, more than 2,130 left-behind children were surveyed in rural areas in six provinces. The survey found that the company of parents, especially the mother, can significantly reduce a child's psychological distress and confusion.

Youngsters driven to despair Feb 25, 2008: Zhang Yangyu, 12, from Taihu, Anhui province, hangs himself because he misses his parents, who left after a short Spring Festival family reunion. The parents moved to a city for better jobs. July 3, 2010: Five students from Xinglin, Shaanxi province, agree to commit suicide together by drinking pesticide in an old temple. A passer-by finds them and all five survive. Four had parents who had moved far away to work. June 15, 2011: Xiao Yang, 10, from the village of Dawang in Xi'an, Shaanxi province, kills himself by drinking pesticide. He was looked after by his grandparents because his parents had gone to work in cities. June 17, 2013: Two girls, Xiao Li and Xiao Yu, both 12, from the village of Xingrong in Jiangsu province attempt suicide by taking sleeping pills after their parents move away. They are found and taken to a hospital. Both survive. Jan 20, 2014: Li Xiaolin, 9, from Wangjiang, Anhui province, hangs himself because his mother, who was working in a city, would not come home for Spring Festival.

"That's because the mother can generally provide much better life-support for the children. More important, the absence of the mother from their children usually occurs if the parents divorce," Liu said.

The conclusion supported the findings of a 2013 report by the All-China Women's Federation, which found that children with absent mothers, and those who live solely with their father are far more likely to drop out of school prematurely.

China has 61 million left-behind children, or children who have been left without care after one or both parents moved away in search of work, according to the federation. It estimates that 46.74 percent of left-behind children have seen both parents move away — 32.67 percent of them live with their grandparents, while a further 3.37 percent live on their own. The federation said these children are most at risk.

The Shangxuelushang report also found that regional factors are major contributors to the children's psychological condition, with those in the northwestern regions registering the highest levels of emotional distress.

"It's an indication that greater efforts should be expended on children in the western provinces to improve their living conditions and to make them more confident about the future,” Liu said.

Li Yifei, deputy director of the Scientific Communication and Education Research Center at Beijing Normal University who is also senior researcher in psychology, said that even trained psychology professionals find it difficult to identify and understand the psychological problems faced by left-behind children.

"Children faced with such problems don't behave differently or give different answers to questions in polls. That's why we need to communicate with them more thoroughly and learn about their concerns," he said.

Liu said it's important for parents to learn to how to communicate effectively with their children. "We found that many children are unwilling to talk with their parents on the phone because they know they will always be quizzed about their performance at school."

"They need what most children need — a story told by their father before bed, a few words of encouragement, and constant reminders that they are loved and missed," he said.