Delaying the age at which a teenager starts drinking is vitally important. So what can a parent do?
• Know the risks: Be informed yourself about the dangers and extent of underage drinking. This will not only help you resolve your position on the issue but will help you see the tell-tale signs of drinking among your own children or their friends.
• Be clear about the rules: An absolute "no" to drinking is the best approach to take with underage teenagers, says Rita O'Reilly of Parentline. If they have one drink, you know they have broken the rule. Whereas if parents are wishy-washy and say one drink is okay, the teenager will inevitably push it to two or three and it is impossible to police.
Set coming home times for teenagers, and stick to them.
"Kids will break the rules," acknowledges O'Reilly. "It's a rite of passage for kids to break rules but they have to know the consequences."
The sanctions must be set out clearly in advance and imposed when merited.
Young teenagers should also know that it's not just mum and dad who forbid drinking. Anybody under 18 who drinks alcohol in a public place is breaking the law. It's also illegal to buy alcohol if you are underage, or to pretend you are 18 in order to buy it.
While it is not against the law to let your own child drink at home, parents should note that it is illegal to allow any other underage teenager to consume alcohol in your house without the consent of his or her parent or guardian.
• Talk and listen to your teenager about drinking: Discuss drinking in a calm and mature way with your child. Be available to talk. Car journeys can provide a good opportunity, says O'Reilly. They can't get away, but it's a finite time and the teenager doesn't have to have eye contact.
Make your own feelings about underage drinking very clear but also listen to their views, says a new HSE publication, Straight Talk - a guide for parents on teenage drinking. "Use everyday opportunities to bring up the subject, for example a storyline in a TV programme," it advises.
Everybody knows an alcoholic - talk about how that life was ruined, suggests O'Reilly. It is also a good idea to give them the means to say no to friends who might be encouraging them to drink.
"Help them say 'no' without seeming like a nerd," says O'Reilly. Prepare them with responses along the lines of: "I really don't like it", or "alcoholism is rampant in my family and I don't want to risk it" or "my mother is a right old bag and she would murder me, it's not worth the aggro".
No matter how much you try to talk to your teenager, there are ones who won't listen.
"You have to keep working at it," says O'Reilly. "Keep vigilant and get in the way of drink, money-wise and time-wise. They will kick up blue murder but this is a parent's role. If you need outside help, call on it."
• Know where your teenager is: Networking with parents of your teenager's friends is essential along with knowing who permits their child to do what. It is much easier for a teenager not to drink alcohol if their close friends don't.
When teenagers say they are staying at a friend's house, check, and find out what adult supervision there will be. Teenagers can be very good at giving only half the story.
"Parents have to be bad-minded and find the missing bits of the jigsaw," says Rose Tully of the National Parents' Council Post Primary. "Build up good relationships with parents of your child's friends."
O'Reilly says to let your teenager know you are talking to other parents by explaining: "We discuss you because you are all very important to us." Also make it clear that arranging to pick a teenager up at the end of an evening out is not about checking up on them but rather looking after their safety.
• Think about your own drinking habits: Changing your own behaviour can be the biggest challenge. Genetics and environment determine if someone is going to become addicted to alcohol, points out Dr Conor Farren of St Patrick's Hospital.
There is nothing you can do about the genes you've passed on to your child, but we do create environmental influences within our own home.
Are you positively inviting your child to drink by having excess alcohol at every family celebration, and sitting with your feet up relaxing with a few drinks every night?
If you drink too much, too often, the chances are your teenager will do the same.