A quarter of UK children aged between 11 and 15 have been offered substances, which can be a worry for many parents. Starting discussions early can be crucial when it comes to legal and illegal highs, says psychiatrist Dr Owen Bowden-Jones.
Discovering your child is taking drugs is every parent's nightmare, and most would go to great lengths to ensure illegal substances - or even legal highs - are never part of their child's world.
But ongoing conversations about drugs with children, starting well before the age they're likely to first be offered them, may be all it takes to prevent experimentation.
Psychiatrist and addiction expert Dr Owen Bowden-Jones -who has written a book called The Drug Conversation to help parents navigate the thorny issue - explains: "What I'm advocating is that parents have a conversation with their children around the age of 10 to 12 years, signposting them to good information, because there's so much misinformation out there."
The book also aims to help parents who are aware, or suspect, their child is using drugs, and want to know what to do.
Research shows less than one in 20 British children under 13 think it's fine to try cannabis out of curiosity, yet by the age of 15, around one in five think it's okay.
And recent official figures show a quarter of UK 15-year-olds admit to having taken drugs at some point, while a quarter of children aged 11-15 have been offered drugs, even if they chose not to take them.
Cannabis is the drug young people are most likely to take, with a fivefold increase in its use between the ages of 13 and 15 years.
Bowden-Jones points out that many children learn often incorrect information about drugs from the playground, the internet, or misinformed friends, so balancing that erroneous advice with credible information from parents at an early age can make a vital difference to the way a child views drugs.
"As well as giving them good information, it shows your child this is a conversation you're happy to have, and that this isn't a taboo subject," he says.
"That's really important, because if they run into trouble with drugs later on, or there's something they want to know about them, they're much more likely to talk to you if you've already opened the discussion," he adds.
He points out that many young people who use psychoactive drugs - drugs that change the way we think, feel and behave - do so only briefly, with just a small proportion going on to use drugs regularly, sometimes because they bring a sense of 'fitting in' with a peer group.
He explains that the adolescent brain develops in a way that makes risk-taking and novelty-seeking more possible, and warns: "Lacking the brain maturity and experience to support good judgement, there is no time when drug use is more likely."
But it's also the time when the brain is most vulnerable to the harmful effects of drugs, which can damage its structure and functioning and disrupt developing neural networks.
If your child uses a drug once or twice at a party, you'll probably never know unless they tell you. But if they're using regularly, you may see the effects, which vary depending on the drug, from being restless and giggly to tired, irritable and confused. But remember, alcohol can mimic some of these symptoms.
Parents shouldn't suggest a child is taking drugs unless they have good reason to think so, warns Bowden-Jones, who says if there's strong, reasonable suspicion, parents shouldn't confront their child but should instead talk to them and explain their concerns, and that they want to help.
Dr Bowden-Jones suggests these top tips:
The Drug Conversation by Dr Owen Bowden-Jones is published by the Royal College of Psychiatrists, priced £12.99. Available now