And it's not just about the kids failing to move on. Parents who have adult children living with them are also more unhappy than parents who are empty nesters.
The Australian Unity Wellbeing report found the happiness and satisfaction of those who lived out of home, was much higher than those who still lived with their parents.
People who live away from their parents also feel more connected to the community and are more satisfied with their future security than those who are living with their parents.
According to the report, the wellbeing of those living with their parents is the lowest it has been in 10 years.
Mel Broom is 28, and she purchased a house and moved away from her parents when she was 24.
After living out of home for two years and moving from regional NSW to Sydney, she went back to the country to live with her parents when she ended a relationship.
She contributed rent when living with her parents and rented out the home she bought to save money on the mortgage.
She became a 'boomerang kid' and has now been back with her parents for two years. She initially only planned to be there for 12 months, and while the first year was great, she's ready to go again.
"Living on my own was fine. I liked it, I liked the space. It's more stress free in terms of I only had to worry about myself," Ms Broom told news.com.au.
"It was my house and I felt I had some independence and was becoming a real adult."
When she moved to Sydney she said she was pushed to move out of her comfort zone and make life decisions on her own.
But since she's been back with her parents, she feels as if she's stepped into a time warp and her parents still presume she's 16, still wanting to have control over her life and make choices for her.
"Now I find my parents have too much say and too much control. They want to know everything about everyone and where I'm going and are trying to influence my decisions," she said.
"I'm almost 30, I'm at that point now where I don't need my parents telling me how to do things."
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Ms Broom said she argued with her parents over the most mundane things, like doing the dishes and washing.
She said her mum would call her while she was on holidays, to check she was doing her washing and asked if she was eating right.
"It's called being an adult, I've done this before," she said.
Living with her parents has also meant Ms Broom has had to compromise her privacy.
"I can be in the shower or getting dressed and mum just walks in and starts talking," she said.
"If I wanted to do something personal, I can't really do that without my parents seeing it or hearing it,"
Despite the frustrations, Ms Broom said there were some upsides to living at home.
There was always a fully stocked fridge and her mum does the groceries and will help Ms Broom out with ironing and washing.
"My mum and I do get along really well and it has been good having other people pay my mortgage while I figured out what I was doing," she said.
"At first I was really happy to be home. I'd been in Sydney for 12 months and wasn't really happy there and I broke up with my boyfriend and things weren't great, I wasn't sure what I wanted and was content with how things were back home. But I think I would be happier at this point being in my own home, with my own things with some space of my own.
"There wasn't really an issue living back at home until recently and I'm ready to step back into adulthood and do me for a while."
Melbourne University family wellbeing expert, Professor Cassandra Szoeke, found the number of young adults living with their parents was growing and usually it was due to financial, social and emotional issues.
She found living with parents could affect a young adult's feeling of independence and parents reported financial and emotional hardships when their children moved back in.
Professor Szoeke and psychologist Katherine Burn analysed 20 studies involving 20 million people to determine the impacts of adult children living at home.
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"Interestingly, the research we examined showed wealthier parents and those who are still married are more likely to have children living at home for longer," Professor Szoeke told Pursuit.
"Whereas early high school leavers from families with a step parent tend to leave earlier and are also less likely to come back."
She said it was usually the unplanned events, like job losses and marriage breakdowns that forced an adult child to move back in with their parents.
"Many parents talk about the lack of privacy and the impact on their social lives, particularly if the returned son or daughter has kids of their own," Professor Szoeke said.
Through their research, Ms Burn found adult children living at home always cost their parents money.
"Even when children do make financial contributions, the parents remain out of pocket," she said.
"This can often cause resentment and conflict. After all, there goes the caravan for retirement or that long-awaited European holiday.
"And parents who live with adult children say they feel they're being taken advantage of, in terms of the household chores."
Professor Szoeke said it was important to pay attention to the issues around boomerang kids or young adults failing to launch.
"The world we live in has greater financial pressures, more social pressures, and there's clearly a situation arising that is causing conflict where conflict doesn't need to exist," she said.
