Children in Chile typically start using alcohol and cigarettes by the age of 13, while cocaine use begins at around 15.
"The figures show that Chile is beginning to outdo big drug-consuming countries such as the United States and that is extremely worrying," said Jaime Ravinet, the mayor of Santiago, as he announced a Live Without Drugs campaign, the first of its kind in Chile.
The campaign combines curriculum-level sessions carried out by specially-trained teachers, along with workshops aimed at parents, and media publicity.
Dr Mariano Requena, a public health expert and member of the Santiago city council, said Live Without Drugs includes plans for door-to-door visits to 50,000 Santiago homes, to inform families of the resources available to help them, and the dangers of drug abuse.
"We expect every one of the nine city councillors to get out and knock on doors throughout the city, just as we did during our election campaigns, " said Dr Requena.
Ten to 15 per cent of Chileans abuse alcohol, giving the country one of the highest rates of alcoholism in the world; more than half the homicides and 40 per cent of suicides take place under its influence.
About half of adult Chileans smoke cigarettes and 42 per cent take tranquilisers which until recently were sold without prescription.
According to the health ministry, recent studies show that drug and alcohol use is shifting toward younger people and women.
Dr Reinaldo Bustos, the man in charge of implementing Live Without Drugs, says that more than three-quarters of Chilean students have consumed alcohol and one in five has sampled marijuana.
A smaller number, 7.3 per cent, have tried a potent, cocaine-based paste to which users become addicted after the third dose; 4.2 per cent have used cocaine itself.
Rock concerts featuring Chilean and Argentine musicians will kick off and close the campaign, scheduled to run until December.
Posters, video clips, seminars aimed at teachers, and training for adolescents identified as peer group leaders, aim to introduce the campaign's key message: "Don't touch drugs". Buttons, caps and bumper-stickers will also announce a drug hotline and other campaign-related information.
Altogether, the government has put up Pounds 165,000 for the campaign, but organisers are trying to raise another Pounds 65,000 from the private sector, to finance more advertising through the media.