If you decide to leave your teenager at home alone while you go on holidays, how can you be certain you won't face a house strewn with beer cans or a daughter in tears when you return, asks Fionola Meredith

IT'S ENOUGH TO make any parent resolve never to leave their son or daughter alone at home until they reach at least 30 or get married, whichever is the sooner.

Given media coverage of debauched teenage parties - along with full details of orgiastic shenanigans on the lawn, lipstick graffiti on the living-room wall and lager cans blocking the toilet - anxious parents may find themselves looking at their sweet, trustworthy teenager with fear and suspicion, searching for the anarchic minx that lurks within.

What would she and her friends get up to if they were left home alone? Would it be a re-run of the Australian bash hosted earlier this year by 16-year-old Corey Delaney - a drunken binge that required a police helicopter and a dog squad to break it up? Or maybe a homage to Jodie Hudson's crazy "sweet 16" party in her mum's £4.4 million (€5.5 million) Spanish residence, which started with young Jodie kitted out in lingerie and devil horns, and ended with 500 strangers running amok and a swimming pool full of furniture? (Jodie's response, posted on Facebook? "Party was fab, but grounded until summer, wat a bitch!")

Or perhaps a version of the costly soirée at the Bowles family home in London last summer, organised by friends of the 14-year-old daughter, where guests caused £15,000 (almost €19,000) of damage, and helped themselves to jewellery, televisions and DVDs in lieu of party bags?

Closer to home, last month, a 17th birthday party in Derry turned into a full-blown riot, as scores of drunken youths attacked the police with stones and bottles, while eyewitnesses reported seeing young teenage girls jumping up and down on PSNI vehicles.

Everything from the ubiquity of internet messaging to the easy availability of cheap alcohol is blamed for huge, booze-crazed teenage get-togethers.

In fact, a recent study by the HSE's Dr Deirdre Palmer and Dr Gary O'Reilly of UCD showed that half of all young people in their late teens are indulging in binge-drinking and drug use, with the first drink taken on average at 13-and-a-half, and the first drug use occurring a year after that.

But while most parents will shake their heads over the lurid headlines and the health warnings, what they really want to know is whether it is safe to leave their own individual child at home alone.

Confronted with a stroppy 16-year-old who no longer sees the allure in a two-week family holiday in a French campsite, and is adamant he or she won't be coming along this year, it's a difficult decision to make.

"My 17-year-old daughter doesn't want to go away on holiday with us this year," says Sue (37), who works as a teaching assistant. "On the one hand, I think she will be perfectly safe at home. We're only going to be away for a week, and she is the most sensible, responsible girl you could meet. In fact, she's very similar to the way I was at that age - hard-working, conscientious, always getting top grades - and I think that was why my parents felt comfortable about letting me stay at home alone at the same age.

"But as soon as my mum and dad were out the door, and on the way to the airport, I got on the phone to my boyfriend, and we spent most of the week in bed together. I remember sneaking him out the back door half an hour before they were due home. And I don't want my daughter getting up to the same thing."

Lone parent Rosie (42), who works as an education and outreach officer, takes a more sanguine view.

"My son is 17 now so I'd be fine about leaving him home alone - although I haven't done it overnight yet. Obviously, he has his own key now and I don't worry about rushing back to be there when he gets back from school any more, and I've left him quite a few evenings fending for himself. But he is at the age when he's experimenting with a little strong drink so I wouldn't like to leave him too long in case he had massive parties.

"I'D LEAVE HIM for a weekend if I had plans and he'd probably love it, although he is very lazy about cooking and domestic chores. There would no doubt be a sink full of dishes and random debris everywhere when I came home."

Child psychotherapist Colman Noctor says that the quandary over leaving your teenager home alone is simply one aspect of the age-old parental struggle concerning the balance between freedom and restriction: too much supervision and you stunt the growth of responsibility; too much leniency and you put the youngster at risk.

"It's notoriously difficult for parents, but this one really is a case of trial and error, and it is specific to each young person. There are 17-year-olds you wouldn't leave for three hours, while there are 15-year-olds you know would be fine all weekend."

As far as Noctor is concerned, the groundwork for such decisions needs to be laid down before they arise.

"You need to instil in your child the idea that successful trials - being left home alone for short periods and keeping the house in one piece - means further trust next time. It's a weaning process."

"When leaving an older teenager alone it is never merely a matter of age, it comes down to trust and responsibility," agrees author and teen coach Sarah Newton. "You should be asking yourself whether they have given you reason to believe that they can be trusted and have shown that they can be responsible. You may have a 16-year-old who is very trustworthy and responsible and a 19-year-old who cannot even be left to make baked beans. You have to be honest with yourself as a parent and ask if you can trust them."

Newton adds that she would never suggest that anyone under the age of 16 is left alone.

While there are no legal stipulations on when a child is old enough to be left at home alone, the ISPCC suggests that in general it should be 16, an age when most young people have sufficient emotional and mental maturity to handle the responsibility.

Even the most chilled-out and confident parents, sipping their holiday sangria, have moments of dread about what antics their teenager may be up to in their absence. But, mercifully, few come home to a scene of devastation.