Almost a quarter of young Australians are facing mental health challenges, with young women twice as likely as young men to be grappling with psychological issues.

Key points: In 2018, 24.2 per cent of young people experienced mental distress, up from 18.7 per cent in 2012

In 2018, 24.2 per cent of young people experienced mental distress, up from 18.7 per cent in 2012 Mental health concerns found to disproportionately affect young women and young Indigenous people

Mental health concerns found to disproportionately affect young women and young Indigenous people Mental health experts unclear why rates are getting worse, call for further action

The latest youth mental health report from Mission Australia and the Black Dog Institute has found rates of psychological distress among young people have risen 5.5 per cent in the past seven years.

These findings are consistent with other recent reports, and paint a concerning picture of worsening mental health in young people.

The question now at the forefront of researchers' minds is: why?

"To be quite honest, people really don't know," said Helen Christensen, director of Black Dog and professor of mental health at the University of New South Wales.

"We are still in the dark as to why mental health and suicide risk has increased in our current cohort of youth, a finding that is not unique to Australia," she said.

In 2018, 30 per cent of young women aged 15-19 experienced psychological distress. Among young men, the rate was 15.6 per cent.

The rate among Aboriginal and Torres Strait Islander young people was even higher: nearly one third (31.9 per cent) experienced mental distress.

James Toomey, CEO of Mission Australia, which surveyed more than 28,000 young Australians, said the findings were "deeply concerning".

"Youth mental health is a serious national challenge that must be tackled as a priority," Mr Toomey said.

"The sheer volume of young people who are struggling with mental health difficulties shows that there remains urgent need for improved access to timely, accessible and appropriate support."

Coping with stress and school problems

For young people experiencing mental health problems, the top issues of concern were 'coping with stress', 'mental health', 'school or study problems' and 'body image', according to the report.

More than a third of teenagers who reported experiencing psychological distress said they were 'very' or 'extremely' concerned about suicide.

While the majority of young people felt they had someone they could turn to if they were in trouble, one in five respondents with psychological distress said they did not.

The most commonly cited barriers to seeking help were 'stigma and embarrassment', 'fear', and a 'lack of support'.

"Parents, peers, schools and health professionals are vital sources of support for our young people," Mr Toomey said.

"It's important they are adequately equipped with the skills and knowledge they need to provide effective support when needed."

Social media has 'massive influence'

For Georgie Cowell, 20, high school was an intensely challenging time.

After being diagnosed with obsessive compulsive disorder at the age of 12, Georgie went on to develop anxiety and depression.

"As school went on, the pressure I put on myself just increased, and the anxiety and depression got worse," she said.

"I started having panic attacks when I was trying to study. I had panic attacks halfway through two of my year 12 exams and couldn't finish them."

At the same time, Georgie started to develop an eating disorder.

"As my eating got worse, I was noticing every third or fourth post on Instagram or article on Facebook ... made me feel worse about the way that I looked, or what I was or was not achieving," she said.

"I think a big part of the issue in mental health with young people today is that so much of our lives are geared towards presenting ourselves to other people.

"[Social media] has a massive influence on eating disorders especially, but also just on general anxiety."

Georgie said the stigma associated with mental health problems made it an isolating experience for young people.

"You don't want to be labelled as that girl with anxiety or that girl with depression, because you just know you're going to be put in a box," she said.

Georgie now presents workshops about youth mental health with the Black Dog Institute. ( Supplied )

Unclear why rates are rising

Given the relatively short period of time over which mental health concerns have increased, Professor Christensen said the rise was "not due to any change in the biology".

"We have to look to societal causes, and there's a large number of those that could be hypothesised," she said.

Uncertainty about 'how the world is going', the pervasiveness of social media, and 'changes in families' were all possibilities, she said.

Increased awareness of mental illness and improved mental health literacy were also factors likely to contribute to rising prevalence rates, Mr Toomey said.

"[It's] helped people to understand that the experiences they're having may well constitute aspects of mental illness or distress," he said.

"We're also seeing young people are experiencing greater levels of bullying and discriminatory behaviour … which are also going to be contributory factors to degrading mental health."

Early intervention is key

Research shows more than 75 per cent of mental health issues develop before the age of 25.

"Adolescence is a critical time in which to intervene, but we also know that young people experiencing psychological distress can be harder to reach," Professor Christensen said.

The report found young people experiencing psychological distress were most likely to go to friends, parents or guardians, or the internet for help.

"We need to continue to provide online and app-based tolls that may be a key part of the solution," Professor Christensen said.

Both she and Mr Toomey said greater investment in preventative mental health programs, as well as increased access to community-based services, were needed.

Mr Toomey said although governments had committed money and resources to providing additional services for youth mental health, many young people simply weren't able to access support when they needed it.

"We've seen Headspace develop in the last few years, and various other resources," he said.

"But we've seen in reports in the past and we see it in this report: access to those services is something that is problematic for some young people, particularly those living in regional and remote parts of Australia."

While returns on mental health investment take "a while to kick in", Professor Christensen said it was "a bit of a puzzle" as to why rates of mental health issues among young people were getting worse, not better.

"We really need to understand what is happening to our young people … and how things are changing for them," she said.

"Because something can be done about it — that's the important thing."