Teenagers are pretending to take drugs to look "cool", research has shown.
A report for drugs helpline Frank, said youngsters in the South East were more prone to talking up their behaviour.
Figures showed that 20% of teenagers questioned said their friends were pressured into faking drug-taking in order to fit in with their peers.
The report which questioned more than 1,000 11 to 18-year-olds across the UK, also said boys were twice as likely as girls to pretend they took drugs.
Almost half the youngsters questioned said the need to fit in with their group dictated their friends' behaviour.
Dr Peter Marsh, director of the Social Issues Research Centre and author of the report, said: "Teenagers today learn to understand who they are by defining themselves through social bonds and affiliations with a peer group.
"As they make the hormone-laden journey from child to adult, they forge a personal identity by first creating a social identity.
"Music tastes and appearance are the obvious ways to define oneself, but the ways in which young people talk about themselves to their peers also helps them to create a sense of self.
'No fashion statement'
"To be an individual, we first need to be one of the lads or lasses."
Darren Hall, spokesman for Frank, said it was encouraging that while young people talked about drug-taking, that they were not necessarily experimenting with drugs themselves.
He said: "It's important to get the facts about drugs rather than relying on hearsay or urban myths.
"Drugs can be dangerous and taking them is not a fashion statement."