R-E-S-P-E-C-T, sang Aretha Franklin in 1967. Four decades later, it could be the mantra for the same people who enjoyed the song then and have just found out that their 20- or 30-something year old is coming home.

Failed relationships, high rents, lost jobs, new babies, saving for a house deposit or having recently returned from abroad are common reasons that drive some adults – termed boomerang kids – to move back into a parent’s home.

Boundaries must be set early on so that the adult child respects their parents’ home. The parents must also treat the child as an independent adult. Ann Marie McMahon, a Dublin-based counselling psychologist, says it’s up to the parents to set the boundaries and to negotiate with the returnee about their plans.

“Are they coming back just for a month till they get a new job? Are they coming back to go away again? Are they coming back just because they want to buy a new house and don’t want to pay rent somewhere else? I think it’s important that both sides establish the circumstances rather than someone arriving back to their old room, literally as if they’ve never left.”

She recommends that parents find out why their child is back, establish for how long they’re back and negotiate terms and ground rules. Otherwise an over-dependency – on either side – could set in. “It’s not healthy,” she says.

McMahon notes that, while it’s fine to move home for a short while, it’s natural to move on and parents should establish how long the child is home for. “If they’re old enough to be living on their own, it’s not good for either side if… the parents treat the 27 year old as if they are 17 and have the dinner on the table and the washing done.”

A parent may be delighted to do this for their adult child but, says McMahon, it is easy to get into a rut. Before they know it, years have passed, the parent is older and the younger person is forced to stay to look after them.

“Set the boundaries very clearly,” she advises. “Establish that adult children pay rent. Certainly if they’re working they’ll have to contribute.”

She says, where the child is saving for a house, a parent could decide that they won’t charge for bills but the child would be expected to contribute a set amount. “It’s also about respect. If they haven’t to pay anything and they’re out earning, there’s no respect.”

Another consideration is that an extra person at home could leave one parent feeling left out if the other starts spending more time with the adult child. Also, according to McMahon, other siblings “could be quite jealous if they’ve moved out and made their own way and parents are favouring this one who’s moved back. It’s much healthier if they all move out.”