The increasing strength of cannabis is causing a major problem for young people in Ireland, according to the Dublin North Regional Drugs Task Force.
A new report shows a steady increase in young adults using MDMA and cannabis since 2011.
It also found that cocaine users in Ireland are not aware of how the strength of the drug is rapidly increasing.
Richie Stafford, one of the main organisers of a National Drug Education and Prevention Forum in Dublin today, said cannabis is the main problem for young people.
This is despite it being seen as a mild drug.
Mr Stafford said: "I think the increase in cannabis use is quite startling and what we have also seen is with the increase in use is an increase in presentations for treatment, especially in adolescent services.
"We have also seen, not so much in Ireland but across Europe, an increase in cannabis potency. They kind of go hand-in-hand.
"It's a stronger drug now because it's stronger, it's causing more problems, it's causing the most harm in terms of presentations for adolescents."
The report also shows problem cocaine-use has increased by nearly 100% in Ireland recently.
Mr Stafford said people are not aware of how much damage it does.
He said: "Cocaine use can detract along with the economy, it's a relatively expensive drug so its use dips during a recession and it seems to be going up since 2016.
"Also, what we are finding out through our colleagues in the organisation is that purity is increasing so it's a stronger drug that people are consuming and they might not be aware of the impact."