The Aislinn Centre says the number of adolescents seeking treatment for alcohol and drug addiction is on the rise.
In its latest annual report, the centre says the workload at its treatment centre in Kilkenny increased by 20% last year.
Some 135 people aged between 15 and 21 were treated at the facility during the year.
The centre says it is concerned that the rate of addiction among young people has never been measured and no coherent steps have ever been taken to tackle the problem.