When Coral Loader worries about her son's future, she speaks about a world of loneliness and struggle.

Key points: The mother of an 18-year-old with autism says there's not enough support for people like her son when they leave school

The mother of an 18-year-old with autism says there's not enough support for people like her son when they leave school UNSW research shows people living on the autism spectrum have a mortality rate almost double that of the general population

UNSW research shows people living on the autism spectrum have a mortality rate almost double that of the general population A professor in disability neuropsychiatry says this is because pathways for people with autism are not easy to find

"It seems to be that once our children become adults, it's like someone has picked them up and has just dropped them off the end of the world into the abyss," Ms Loader said.

"People don't see adults with disabilities."

Her 18-year-old son, Corey, lives on the autism spectrum but has struggled with depression and once attempted suicide.

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"All these little things became a brick wall and he hit it and he hit it hard," Ms Loader said.

Like many others, Corey faces a difficult transition into adulthood, with recent research from the University of NSW showing that people living on the spectrum have a mortality rate almost double that of the general population, with suicide and self-harm a significant concern.

A need to contribute, find purpose

Ms Loader says Corey is a proud member of the Scouts and even helps out the local fire brigade in Buninyong, near Ballarat.

But he is vulnerable to sensory overload and severe self-doubt, making employment or future study a difficult prospect.

Despite some mental health issues, Corey Loader participates in Scouts. ( Supplied: Coral Loader )

"He hates to fail, whenever he sits for a test he'll usually get it wrong because he'll have the right answer straight away but he overthinks and then he'll change it," Ms Loader said.

"I've got friends whose children are 16, 17 and are disengaged from school and they live in their bedrooms, and I don't want that for my son.

"I don't think a lot of parents do, but we don't have a lot of options. There's not a great deal of support."

Ms Loader said she was desperate to find a meaningful occupation and purpose for her son as he entered adulthood.

"I feel like a failure because we've put everything in place, everybody who knows Corey sees him as a great achiever and that great achiever is now hitting the wall," she said.

"We can't seem to find something to support him for the rest of his life, to keep him feeling like he's contributing to the world."

Troubling trends in mortality, mental health

Professor Julian Trollor, from the Department of Developmental Disability Neuropsychiatry at the University of New South Wales, researched the mortality rates, health risk factors, and causes of death among 36,000 people with autism in New South Wales.

"People with autism have about 1.6 times higher risk of death, while people with autism and intellectual disability have about 2.3 times the risk of death," he said.

But Professor Trollor said there was a significant difference in the causes of death for people on the autism spectrum, compared to the rest of the general population.

"About 13 per cent of all deaths relate to accidents, injuries and poisonings, which include deaths from suicide, but in our study, in people on the autism spectrum, overall 23 per cent of all deaths were in this category," he said.

"Fifty per cent of all deaths in people with autism without intellectual disability were accounted for by this category.

"This is a much bigger proportion than we'd expect and we think it underlines the significant issue of untreated or poorly treated mental ill-health for people on the autism spectrum."

'A cycle of isolation'

Professor Trollor said his research suggested about half of adults on the autism spectrum experienced depression and anxiety, and had "high mental health needs, but often are struggling to access appropriate services and support that might help".

"Often care pathways for people with autism are not as obvious," he said.

"You may not know how to seek the support and also when you do get to the support, it may not be support tailored to your needs."

But Professor Trollor also said there were social needs that fell between government-funded support programs and the family care given to people on the spectrum as they grew up.

"They're lacking connectedness to people in the community, with friends, they're lacking the support they'd otherwise have," he said.

"This often feeds into a cycle of loneliness and isolation and lack of ability to mobilise those supports when people are really distressed.

"There's often a problem with engaging in social situations, difficulty with interactions that help us cement or glue us to each other in society, and a difficulty in developing and maintaining friendships, and relationships and intimacy — that can be a real challenge for people on the autism spectrum."

'The community will be his family'

Ms Loader said most Australians did not have an appreciation for the difficulty facing adults living on the spectrum.

"They're being forced into either a disability pension or to recluse into their bedroom," she said.

"It's quite difficult for people to say just drag them out but it's just not as simple as that."

It's a sentiment Professor Trollor said must be addressed by governments and the broader public.

Coral Loader and her husband hope that by getting Corey involved in community activities now, he'll maintain social connections as an adult. ( Supplied: Coral Loader )

"Our society is not yet equipped to support people with autism and I think this is a lack of disability awareness in the community — we don't value difference," he said.

"People on the autism spectrum are simply part of a neurodiverse population that enriches our society."

But Ms Loader said she was hopeful for her son's future, with her family making special efforts to make sure he was involved in as many community groups and activities as possible.

"If my husband and I are no longer here, it's the community that will be his family."