Illustrative image. – File photo

The survey, part of a stress research project on teenagers by Da Nang Psychiatric hospital in recent years, revealed that the problems often involved worries about poor study at school.

Doctor Tran Hai Van, head of the child mental ward at the hospital, said high school teenagers were often stressed out by too much study or were criticised by their parents for producing poor results.

"Many said they were tired out, but were forced to undertake extra study." he said. "Failing to understand lectures and missing out on merit certificates adds to their pain."

Van said some teenage patients in the hospital's mental ward were found to have reserved all their time for study because of parental expectations.

She said the survey showed 88 per cent of students were scolded and punished by their parents if they did not perform well.

Hospital psychologist Dam Que Anh said high-school students had big change in psychological make-up and character during puberty.

They often neglect their studies, have disputes with friends or fall in love with school-mates. However, they cannot share their problems with teachers or parents," Anh said, saying most shared their worries and sadness on Facebook or searched for information on the internet.

Vice director of the city's education and training department, Nguyen Minh Hung, said the results of the survey would help the department modify its education strategy.

"We will organise a mass survey of all student at high schools in the city and map out a master plan to deal with psychology disorders at school," Hung said.

Da Nang was the first city in Viet Nam to carry out the 2012-14 pilot project, which aims to create positive environments in schools.