Pupils can be identified as potential binge-drinkers before they have had their first taste of alcohol, according to new research.
Academics from the Institute of Psychiatry at King's College London have devised a method for predicting - and another for intervening to prevent - binge-drinking among pupils at the start of secondary school.
More than 2,400 teenagers from secondary schools across London completed a series of personality profiles, which measured their tendency towards impulsivity, thrill-seeking, anxiety and pessimism.
Those who scored especially highly on any one test were at particular risk.
Lead researcher Patricia Conrod said: "Those types of personalities tend to be more likely to develop depression, anxiety, anti-social behaviour, risk-taking behaviours. But, at 13 years of age, most of them haven't had anything to drink, haven't tried any drugs, haven't started smoking."
Trisha Jaffe, head of one of the participating secondaries, Kidbrooke School in south-east London, was surprised by those pupils revealed to be at greatest risk of future alcoholism.
"It wasn't always those you would have guessed," she said. "When some of your most able kids are coming up as risk-takers with impulsive attitudes, you're thinking: 'Goodness. That really does put them at risk of not achieving their potential.'"
The researchers also developed a programme to counter binge-drinking before it began - but there was no mention of alcohol or drugs.
Instead, pupils were offered targeted intervention sessions, designed to tackle the behavioural problems highlighted in their personality profiles.
Teenagers with problems managing anxiety were offered advice on avoiding catastrophic thinking, which often exacerbates existing anxieties, while those with a tendency to impulsivity were taught to think before reacting.
"Impulsive people don't tend to be that good at self-analysis," said Ms Jaffe. "We're helping them to become more self-aware, to make better choices. If you don't understand risks, how can you make informed choices and avoid the worst dangers?"
Dr Conrod and her colleagues found that these intervention sessions delayed the onset of drinking - "and therefore binge-drinking, because that's what adolescent drinking is" - among participants by between six and 12 months, compared with a control group.
"One of the symptoms of problematic alcohol use is using too early - in early adolescence," she said. "Delaying the onset of drinking leads to the decreased likelihood of problem drinking. It gives them non-drinking social skills and protects them into later adolescence."
But Dr Conrod and Ms Jaffe both stress that the programme will not pre-emptively label pupils as alcoholics.
"Risks can be alcohol or drugs," Ms Jaffe said. "But they can also be other kinds of behaviours that affect a young person's life.
"It's about getting to know your own behaviours, and managing them better. It's about being more successful in your own life."
50 per cent of British 15-year-old girls say they have been drunk at least twice.
44 per cent of British 15-year-old boys say they have been drunk at least twice.
Binge-drinking is more common among 16 to 24-year-olds than any other age group.