At 14 years old Jahnesta Carriage reached out for help, she was self-harming and struggling with depression and anxiety, but the support she got made her feel worse.

Key points: Young people and parents speak out about Headspace mental health service, saying it couldn't help them

Young people and parents speak out about Headspace mental health service, saying it couldn't help them Experts say the current headspace model has limited clinical effectiveness

Experts say the current headspace model has limited clinical effectiveness Both sides of politics have promised to open more clinics, but experts say that's 'politically easy'

Like thousands of other young people in Australia, she was referred to Headspace, a youth mental health service, that since 2006, has operated all around the country under its iconic green banner.

"I never felt like they truly knew what to do with a kid with as severe depression or anxiety as me," she said.

Jahnesta received eight free psychologist appointments at the centre, but she felt hand-balled between different workers and like she made little progress before her sessions ran out.

"Really, to sum it all up, Headspace was just a waste of time," she said.

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Her mental health deteriorated and at 16 she attempted suicide.

"I thought that I was helping her, and trying to get her some help and get her on antidepressants, but it basically just pushed her over the edge," her mum Lynn Gilpin said.

"[Headspace] is like looking at a beautiful shopfront and then going in and seeing there's nothing there. It doesn't offer you anything."

After years of government investment in Headspace, doctors, social workers and former clients are urging the Government to stop opening new clinics and consider the shortcomings of the model.

Many in the sector believe young people with complex mental health challenges, like Jahnesta Carriage, have nowhere to turn.

Headspace 'only serving youth in the Goldilocks zone'

The government-funded foundation was set up under the Howard government, designed to be a one-stop shop for young people to drop-in and get medical, social and emotional support.

In the past two decades, successive governments have invested millions of dollars into the model, opening more than 115 centres around Australia — with more in the works.

More young people than ever expected are seeking support from Headspace, Professor Ian Hickie says. ( ABC News: Isabella Higgins )

"There's rarely a week that goes by where an issue isn't raised, where young Australians are saying we need more support," Headspace chief Jason Trethowan said.

"More young people are reaching out to Headspace; part of that challenge is keeping pace with people seeking help. But the need is significant."

One of Headspace's key architects, Professor Ian Hickie, said he believed it had become a victim of its own success, with more young people than ever expected seeking support.

"The Headspace model was never set up to deal with more complex presentations, people with impairments already established, those who had complex mixes of anxiety, depression and substance misuse," he said.

"Opening a new shop in every town in Australia simply will not solve the problem … I think that simplistic primary care model is no longer what is required.

"Fifteen years later it needs depth and sophistication.

"It must be relevant to the populations it seeks to serve."

Young people needed to be in "the Goldilocks zone for getting into Headspace," said George Patton, a professor of adolescent health research at the University of Melbourne.

"You've got to have enough problems to warrant the service, but if you've got too many problems you've got to go somewhere else, and in this system there might not be anywhere for you to go," he said.

Professor Patrick McGorry was also integral in setting up Headspace in Australia and is still on the board.

He said the service was a "trusted entry point" but could not meet the needs of all young people on its own.

"We call it the missing middle. They're too sick for Headspace and not sick enough for the very limited provision of care through state government services," he said.

"They're really in deep trouble and this is where a lot of the preventable deaths [suicides] are occurring."

Headspace chief Mr Trethowan conceded "not everything can be provided" by the service.

"For those who have more severe mental health challenges, it's up to us to identify other avenues for them to find help, whether that be through the public mental health system or other services in other communities."

Opening more centres is 'easy for politicians'

Experts agreed Headspace had become popular with not only young people but also politicians, with recent governments boosting funding and opening more clinics.

On the campaign trail of this federal election, both Labor and the Coalition have committed to opening even more centres.

In this year's federal budget, the Morrison Government set aside nearly $500 million of new funding for youth mental health system — Headspace would receive more than half of that.

The Coalition said during its time in government they had spent an "unprecedented" amount on improving the mental health systems and Headspace was an important piece of that puzzle.

"Mental health is also more than the absence of mental illness but encompasses all aspects of our lives. Headspace brings this holistic view to youth," a spokeswoman for Federal Health Minister Greg Hunt said.

"For young people with severe or complex mental illness, the Government established the Early Psychosis Youth Service at six Headspace centres across the country. These have received $287 million."

The Opposition has pledged more than $100 million in funding for mental health services and suicide prevention programs for Indigenous Australians, however it's yet to announce how much money a future Labor government would allocate to Headspace.

Despite the investment, there has only been one independent review of the organisation's clinical effectiveness in more than 13 years of operation.

The findings of that study should have triggered alarm bells, according to Mr Patton who was involved in the 2015 review by the Social Policy Research Centre at the University of New South Wales.

"The single evaluation we have suggests that the gains are not that big," he said.

"Adolescents who were attending Headspace were doing a little better than if they had not attended, but the difference was not huge."

The review found about 70 per cent of clients experienced an insignificant change or no change in their psychological distress levels.

About 23 per cent had an improvement while 9.5 per cent experienced a noticeable deterioration.

"Opening more Headspace clinics is easy for politicians as opposed to doing that long-term planning and really assessing the need," Professor Patton said.

Australia currently spends 7 per cent of its health budget on mental health, about half the national spend in the United Kingdom, he said.

"I think now is a really good time to take stock of what [we] need to be investing in beyond Headspace … there's a case to spend more, but also spend better."

The Government said they also put $50 million a year into high-need mental health services run by public health networks around the country.

"We are committed to ensuring that all Australians have access to the best possible mental health care when and where they need it," a spokesperson for the Health Minister said.

"However, we are also determined to invest in prevention and early intervention as the best way to protect mental wellbeing."

Headspace received funding to support Indigenous youth

The 2015 review found those from an Indigenous background, like Ms Carriage, were over-represented among those who were clinically worse-off after visiting Headspace.

Since the beginning of the year, the Aboriginal community have called out a "youth suicide crisis," with dozens of Indigenous young people ending their lives.

Headspace has received targeted funding to support young Aboriginal and Torres Strait Islander young people.

The ABC spoke to other young Indigenous people who found Headspace services did not meet their needs.

Cody, 20, Brisbane, Queensland

Cody Martin struggled with mental health issues for much of his teenage years. ( ABC News: David Sciasci )

"I went twice to Headspace because I had issues with depression, but they didn't really help at all," Cody said.

"Filling out all these forms and assessments on an iPad was really complicated and stressful.

"I found I felt worse after I went in than better. I felt even more depressed. The advice they gave me wasn't really useful."

Morgan*, 24 Coffs Harbour, NSW

"I only visited once, overall the experience was very good and the staff were nice, but I would have preferred to see an Aboriginal worker just for more of a cultural understanding," said Morgan, who didn't want to use her real name.

"They just didn't understand the issues that Aboriginal people face mostly, because they haven't experienced it.

"They don't really have an understanding of our current issues and I found it hard to relate to them."

Mr Trethowan said Headspace took its approach to "the social and emotional wellbeing of young Aboriginal and Torres Strait Islander people" very seriously.

He said the organisation had adapted its approach across the decade to better suit young Indigenous people, but it was still learning from the feedback they received.

"We know that their mental health and wellbeing is is impacted by colonisation, by poverty, by trauma," Mr Trethowan said.

"There are many situational factors that young Aboriginal and Torres Strait Islander people are having to deal with."

Vulnerable youth 'slip through the cracks'

Keiran Kevans spends most of his time helping vulnerable youth, running Glebe Youth Service (GYS) in inner-city Sydney.

Kieran Kevans said many young people who used their drop-in service were battling mental illness. ( ABC News: Isabella Higgins )

"Mental health is a big issue for a lot of kids we work with, whether we're talking about low-level anxiety and depression, which is quite common among these kids, right through to the gamut of mental health problem that people experience," he said.

Figures suggest one in four young people in Australia have a mental health issue.

It often takes months to build up enough trust with young people to begin a mental health intervention, and even then it's difficult to know which service to refer them to, Mr Kevans said.

"It's simply not enough to just make a referral and say, 'hey, you've got a mental health issue go and see that service'. We need to make sure they don't slip through the cracks.

"When we are talking about particularly vulnerable young people that doesn't work so well … it works when mental health workers embed themselves in the organisation."

The current youth mental health system just "has the foundations built, but is missing the rest of the house," Professor McGorry said.

"Mental health issues are really short-changed in this country, probably only about a third of the people who need help [are] getting it.

"Even then the quality of that [care], is below that the quality of what you see in other areas of health care."

Those in charge of Headspace said they believed it was part of the solution and that it was working with many community organisations to increase its engagement with youth.

"I think Headspace is an avenue to invest in the missing middle," Mr Trethowan said.

"General practice needs greater support for working with people of all ages around the mental health challenge, and the state mental health systems also need greater investment."