A clinic in Vancouver began recruiting heroin addicts to give them free drugs, as part of a national study that's the first of its kind in North America.

The North American Opiate Medication Initiative plans to enroll 470 hard-to-treat addicts in Vancouver's Downtown Eastside, Toronto and Montreal â about 157 people at each site.

About half the volunteers in the $8.1-million study will receive free, pharmaceutical-grade heroin for 12 months, which they will administer themselves in a clinic under medical supervision.

The others â a control group â will be given methadone, a synthetic narcotic that helps addicts overcome their heroin cravings and prevents symptoms of withdrawal.

After a year, the group on heroin will gradually be moved into the methadone program or to another treatment method.

Researchers, led by Dr. Martin Schechter of the University of British Columbia Faculty of Medicine, hope the addicts will make positive changes to their lives because they won't have to steal or prostitute themselves to get money for drugs.

The doctors also hope that by giving the heroin away, they will reduce overdoses and HIV infections.

Ultimately, they hope people taking part in the program will be able to kick their drug habits.

There are thousands of heroin users in the Downtown Eastside, which has one of the highest proportions of drug addicts in North America, but only six people a week will be accepted into the program over a six-month period.

Anne Livingstone, project co-ordinator for the Vancouver Area Network of Drug Users, said she has some questions about the recruitment process, but she's happy to see the clinic finally getting off the ground.

"I guess I was always a bit cynical in the sense that it would just die on the vine and it wouldn't be pursued, and I just have to say I'm really pleased that they persisted."

The project has drawn fire from critics including U.S. officials, who argue that Canada is too lax in cracking down on illegal drug use.

The Vancouver neighbourhood already has the continent's first injection site for heroin addicts.

The prescribed-heroin clinic may be a North American first, but similar programs have been offered in Europe.

In a similar project in Switzerland in the 1990s, fewer than 10 per cent of the addicts quit taking heroin â but the crime rate among addicts dropped and the job rate went up.

It's expected the free heroin will be available in Vancouver by the middle of next month. The Toronto and Montreal trials begin later this spring.

The Canadian Institutes of Health Research is funding the study, which is approved by Health Canada.