In 2001, the world's media descended on one of Lisbon's poorer districts. Portugal had become the first country in the EU to decriminalise drug use and the coverage painted a bleak picture of the continent's "most shameful neighbourhood" and "worst drugs ghetto" where addicts openly injected heroin.

This "ultra-liberal legislation", it was feared, would lead to drug tourists descending on Portugal. The leader of the country's People's Party, Paulo Portas, said plane-loads of foreign students would head for the Algarve for "sun, beaches and any drug you like".

Yet, 10 years on, Portugal's drug policy is being held up as the model for other countries to follow. Rather than criminalising people found in possession of drugs, they are sent to a "dissuasion commission" for treatment and the results have been spectacular.

Portugal now has one of Europe's lowest lifetime usage rates for cannabis and heroin abuse has decreased among vulnerable younger age-groups.

The share of heroin users who inject the drug has also fallen -- from 45pc before decriminalisation to 17pc today.

Portugal's previously high rate of HIV has also plummeted with drug addicts now accounting for only 20pc of all new cases, down from 56pc before. In 2001, new diagnosis of HIV was running at about 3,000 a year. Now, it's down to fewer than 2,000 per annum.

Other measures have been just as encouraging. Deaths of street users from accidental overdoses also appear to have declined as has petty crime associated with addicts who were stealing to maintain their habit.

Furthermore, recent surveys in schools suggest an overall decrease in drug experimentation. It's estimated that as much as €400m has been taken out of the illegal drugs market, with Portuguese police now focusing their attentions on high-level dealers rather than small-time operators.

"It's been a resounding success," says Jose Pinto, Chancellor of the Embassy of Portugal, Dublin. "Walk around any of the cities and you will see that it is different to 10 years ago.

'Drug-taking or people being strung-out is not something you would see as much on the streets any more. And the country has not become a destination for drug tourists at all. It's nothing like Amsterdam, where there has been a tolerance of some drugs.

"Some of the right-wing and conservative politicians thought the policy of treating drug addicts rather than punishing them would not work, but it has. The country had a significant problem with drug abuse and the rate of HIV infection in the 1980s and 1990s and now the rest of the world is looking at Portugal and what it has achieved in just one decade."

And Ireland is set to join the list of admiring onlookers. Joao Goulao, the architect of the policy, will be the keynote speaker at the National Drugs Conference to be held in Dublin on November 3 and 4.

Tim Bingham, who is one of the organisers of the conference, hopes Goulao's visit will help foster debate on Portugal's visionary approach.

"There is a great deal we can learn from Portugal," Bingham, chairman of the Irish Needle Exchange Forum, says.

"Here, we criminalise anyone caught in possession of drugs. In Portugal, people are treated humanely and they are helped to overcome their addiction without fear of being considered a criminal.

"It's important to remember that 'decriminalisation' and 'legalisation' are two very different things. You can't just walk down the street in Portugal smoking a joint or shooting up in the street.

"The drugs are confiscated and you are compelled to undertake a rehabilitation programme. It's still illegal to be in possession of drugs, but the consequences are very different from here."

The number of addicts registered in drug-substitution programmes rose from 6,000 in 1999 to over 24,000 in 2008, reflecting a huge rise in treatment but not drug use.

"Before decriminalisation, addicts were afraid to seek treatment because they feared they would be denounced to the police and arrested," says Manuel Cardoso, of the Institute for Drugs and Drug Addiction, one of Portugal's leading drugs-prevention agencies.

"Now they know that they will be treated as patients with a problem and not stigmatised as criminals."

The aim of the dissuasion commissions, which are composed of psychiatrists, social workers and legal advisers, is to encourage addicts to undergo treatment and to stop recreational users falling into addiction.

They have the power to impose community work and even fines, but it is a sign of the success of the programme that they rarely have to resort to these measures.

Roughly 7,500 people a year are turned over to the commission by the police but nobody carrying anything considered to be less than a 10-day personal supply of drugs can be arrested, sentenced to jail or given a criminal record.

"Here, if you're caught in possession, you will have a stain on your record for life," Tim Bingham says. "Think how hard it is to rebuild your life if you've got a criminal record, especially in a climate like this where jobs are now so hard to come by. In the UK, it's a bit more progressive because some records are erased after five or six years."

Portugal's success story, meanwhile, has attracted the attention of some of the world's most successful people. Luminaries such as billionaire investor George Soros, former UN secretary general Kofi Annan and entrepreneur Richard Branson are part of an influential think-tank, the Global Commission on Drug Policy, and they are advocating decriminalisation in the so-called 'war on drugs'.

"Locking people up in prison is not the answer," says Branson. "Treating the problem as a health problem, rather than a crime, is. In the few countries in the world where they have decriminalised the taking of drugs, Portugal being the best example, the amount of heroin addicts has dropped by half. There's been a drop in the HIV figures and the amount of cannabis use is the lowest in Europe."

This punishment-does-not-work view is endorsed by one of America's leading drug policy analysts, Mark Kleiman. "We should take seriously the possibility that anti-user enforcement isn't having much influence on our drug consumption."

Ireland is no stranger to drug problems with an estimated 20,000 people considered to be addicted to heroin. Some 15,000 of them are Dublin-based and they are a highly visible presence on the streets of the inner-city, much to the chagrin of local residents and tourists.

"Much of Irish society regards addicts as social delinquents rather than people in need of help," says Tony Duffin, director of one of Ireland's best regarded drug treatment centres, the Dublin-based Ana Liffey Project. "But that attitude only exacerbates the problem and it leads to even greater marginalisation than before."

Tim Bingham notes that even the language used to describe addicts suggests we have a long way to go to reach Portugal's stance. "How can people regularly called 'junkies' feel any sense of communion with the wider populace? The lack of tolerance or understanding of society is very damaging.

"The problem of drug addiction won't just go away if it is ignored, we need real vision if anything is to change. And the lead to follow comes from a country in much the same situation economically as Ireland -- Portugal."

Indo Review