Dr Bobby Smyth, consultant child and adolescent psychiatrist in south Dublin said spiralling levels of cannabis use had now led to a growth in drug debts, ultimately leading to suicide in a small number of cases.

Dr Smyth said the most significant change was the usage of cannabis and the associated change in the way it is sold.

He said it was now not uncommon for people to smoke up to €50 worth of cannabis a day — a spend comparable to someone with a heroin addiction.

However, cannabis dealers are allowing clients to build up debts of hundreds of euro, which they then struggle to pay, often leading to the debt increasing while usage continues.

“They are spending the sort of money on cannabis now that we would associate with heroin four or five years ago.

“It means you can end up with debt of a few hundred [euro] and it can build to a few thousand.”

That brings intimidation and threats of physical violence, which Dr Smyth said can cause “huge distress”.

“Everyone is struggling to know what to do about it. The guards cannot act unless someone names the individual threatening them.

“There have been a number of suicides that have occurred in parts of Dublin I deal with that have been linked back to cannabis,” he said. “I am hearing it anecdotally but I am hearing it anecdotally from different sources and related to different suicides,” he said.

“I am seeing people who are acutely distressed about cannabis and the issues around it.”

He said that in addition to difficulties with drug use, drug debts and the threats associated with that often lead to stress and therefore further usage, as many users have a “limited range of coping skills” and also feel guilty for involving their parents in helping them pay the debts.

“That issue of indebtedness is part of the reason people are coming for treatment.”

He said it was not limited to Dublin and was instead a national problem — a view echoed by the Aislinn Centre in Co Kilkenny which provides treatment programmes for adolescents abusing drugs.

Breda Cahill, general manager at the Aislinn Centre in Ballyragget, said the average age of clients presenting to their service for problematic cannabis use was now 16.

She said: “We would have noticed a lot of families and a lot of parents with a lot of debt to pay.

“Parents are sometimes not aware that the debt is there until it’s far too late.”

Dr Smyth said the weed being smoked was more potent than hitherto and was now the main form of cannabis available.

He also said that some people had gone to social workers over the threats being made regarding drug debts and in some cases families had been relocated.