After becoming established in poor housing estates in Ballymena, Co Antrim, five years ago, the use of hard drugs, particularly heroin, has spread inexorably to Belfast and other parts of Northern Ireland.
Previously, the North had been largely free of the drug, although soft drugs were available. One of the main reasons was that all the paramilitary organisations were adamantly set against hard drugs.
A few years ago, anyone found dealing or even taking heroin in an area where the paramilitaries held sway would almost certainly be murdered.
Cannabis, however, has been widely available throughout the city and is used by paramilitaries themselves. Members of the UDA have been heavily involved in the supply of cannabis for years.
According to loyalist sources, Protestant paramilitaries are said to have branched out into supplying other drugs including cocaine and heroin.
According to sources in Belfast yesterday, a small heroin trade has become established in the south of the city, where there is a religious mix and a student population, and it is possible to deal in the drug away from the attentions of paramilitaries.
However, in the past year hard drugs have moved into Catholic west Belfast and the lower Shankill. Sources in west Belfast yesterday reported that the deaths of the three young men, and possibly the collapse of another, resulted from taking heroin. They were together earlier in a pub on the Falls Road.
Much of the spreading drug abuse in the North is occurring in areas where the worst social problems arise. The bleak housing estates around Ballymena and Antrim town were ideal breeding grounds. And initially the drug was being supplied from similar areas of social dereliction in Glasgow, where the drug has become an infestation.
The so-called "dump" housing estates in Co Antrim have had great difficulties arising from drugs. A settled member of the Travelling community died of a heroin overdose in an alleyway in Ballymena last month. There have been outbreaks of fighting, and last week a young man received a serious wound from a machete.
Some local activists, including former paramilitaries, have tried to control the problem and have been attacked for their efforts.
A member of the Progressive Unionist Party (PUP) and former UVF figure, Denver Smith (32), was beaten to death on New Year's morning last year when he was attacked by a drugs gang in the housing estate in Antrim where he lived. In retaliation, the UVF shot dead a young man, Ciaran Cummings (19), last July 4th.
Predictably, addicts in the North are turning to the heroin market in Dublin, where there is an addict population estimated at over 15,000.
One Belfast taxi-driver told The Irish Times of driving a young man from Belfast to Ballymun in north-west Dublin, and back again. His family later paid the taxi fare.
Only recently have the authorities in the North appeared to wake up to the problem.
Parents of addicts in Ballymena have had to form self-help groups to try to support their children. Some of the family groups in the Co Antrim area have started visiting similar groups in Dublin seeking advice. Families in Ballymena said last year their main concern was that the Department of Health and Social Services (DHSS) did not provide help in the form of needle exchange or addiction substitutes.
Control of the DHSS has passed from the Northern Ireland Office to the Assembly and the heroin problem is now the responsibility of the Sinn Fein Health Minister, Ms Bairbre de Brun.