A couple who blame their teenage son's death on an internet phenomenon called the "choking game" want more people warned about the dangers.
Will Hadley, 14, from Stoke Golding in Leicestershire, was found dead in his room in May 2014 by his parents.
They believe he choked himself by accident after seeing videos about it on the internet.
Edward Timpson, minister for children and families, said it was "a serious and dangerous practice".
He said the government had raised the problem with the UK Council for Child Internet Safety and was also "taking a range of actions to improve child safety online".
Mr Timpson also said the issue had been raised with YouTube, which has a policy of removing any videos promoting dangerous activities from its website.
But the Hadleys said: "We want something to be done about this. We think the response has been really poor - we have been given lip service from pretty well everyone.
"We want every GP and school and coroner and police force in the country to be made aware."
An inquest in Loughborough recorded a verdict of accidental death, but the "choking game" was not mentioned, they said.
Mr Hadley added: "It was an absolute total shock. He was one of the happiest kids, he was full of life, no problems at school and we got on great with him.
"You try to prepare your kids for life… those threats and dangers, but how can you deal with something you have never heard of?"
Nigel Mathers, of the Royal College of General Practitioners, said: "The general incidence of self-harm, of which this may or may not be a form, is certainly known to be increasing among adolescents."
He said "an awareness campaign among GPs with some signposting to management strategies would be useful".