Some 40 per cent of school pupils aged 15 and 16 have tried drugs, with little difference in usage between girls and boys, according to a report published today.
Experience of cannabis in the 15-16 age group increased by 8 per cent to 40 per cent between 1999 and 2003. The use of solvents was also particularly high.
The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) published a wide range of figures that showed young Irish people have one of the highest rates of drug-use in Europe.
The EMCDDA annual report showed Ireland ranked joint third for lifetime experience of any illicit drug in 2003, with cocaine-use on the rise.
The statistics are open to interpretation, however, because of differences between states' reporting methods and time periods covered.
The figures, based on Irish research submitted to the EMCDDA, show 18 per cent of people aged 14-34 had tried cannabis, which is a slight fall, while 2 per cent had tried cocaine - one of the highest rates of the 35 countries studied.
There was a 3 per cent increase in the number of schoolboys who had used cannabis, while the number of schoolgirls increased by 10 per cent to 39 per cent between 1999 and 2003.
Current use for boys dropped 2 per cent over the period but increased for girls, from 11 to 17 per cent.
Irish figures reflected the general increase in cocaine use, and the drug is now the second most popular recreational drug in Europe. Cannabis remains the most popular, although its rate of use stabilised while ecstasy use fell.
The Health Research Board, which provided the figures, said cocaine use in the past month among the general population was around the EU average at 0.3 per cent.
But 2 per cent of the 15-34 section has tried cocaine - among the highest in Europe. Around half of all cocaine users tried it for the first time before they were 20 years old.
Cocaine purity levels were reported as being lower in Ireland than elsewhere in the EU, and some 31 per cent of the 4,671 reported seeking drug treatment in 2004 were cocaine abusers. This was just below the European average.
Almost half of treated cocaine cases were aged between 20 and 24 years, while 16 per cent were aged between 15 and 19 years.
Although there were no figures for cocaine-related crime, the report noted that prosecutions relating to cocaine had surpassed heroin-linked crimes.
Polydrug use - the taking of more than one drug type at a time - was also on the increase. Ireland also recorded one of the highest rates of opiod use - mainly heroin
The survey also showed the cost of illegal drugs was falling across Europe.