Advocates say an alarming number of children are going to emergency departments due to a mental health crisis.

Victoria saw a 46 per cent increase in children presenting to the ED for self-harm, stress and anxiety, mood, behavioural and emotional disorders from 2008 to 2015, while ED presentations in NSW by 10-19 year-olds for suicidal thoughts, self-harm and intentional poisoning increased by 27 per cent between 2010 and 2014.

Researcher Susan Sawyer says the rise in young people turning up at the ED for mental health treatment should be seen as “canaries in a coalmine”.

“[The increase] is clearly reflecting that the system is failing,” Professor Sawyer told the ABC.

“In the context of the very major investments Australia has made in mental health care over the past few decades … there's some real questions this data raises about what we need to do differently.

“Mental health presentations to EDs are still way in the minority in comparison to physical health conditions, but seeing a more than three-fold increase in presentations in a seven-year period is clearly very concerning.

“The real question is … why are these people presenting to emergency departments? At what level in our system is this reflecting failure?”

Professor Sawyer said not enough is known about how well current services meet minimum clinical standards.

“While [the Government's youth mental health service Headspace] has increased access to mental health care … we know remarkably little about the effectiveness of that model of care, which is disappointing given the extent of investments that have been made,” she said.

Professor Patrick McGorry, executive director of Orygen, the National Centre of Excellence in Youth Mental Health, says that the lack of specialised mental health services leaves few options for young people with acute and complex mental disorders.

“In the primary care setting, you've got GPs and psychologists … and the duration of care is usually only a few sessions — five or six, maybe up to 10. It's OK for mild to moderate problems,” he told reporters.

“But if you come in with a more complex problem, you need a multidisciplinary team … and the public system is extremely under-resourced, and not able to provide that to most people who need it.

“The only alternative is for them to sit out there, deteriorate, and either develop a crisis of some sort — a suicidal attempt or in some cases a violent or aggressive attempt — and then they end up in the ED or with the police.”

Professor McGorry said there is an urgent need for “more specialised and assertive community programs” to back up the work of Headspace.

“That's the kind of structure that's missing – community hubs with multidisciplinary teams, more expertise and a longer tenure of care, so people can actually stay in the system for as long as they need to,” he said.

The experts also want more funding for crisis support lines like Kids Helpline and Lifeline.