Each time, Mr. Vincent played the role of guinea pig in a controversial, three-year, government-funded experiment that supporters hope will change the face of addiction treatment in this picturesque but drug-riddled western port city.
The findings of the North American Opiate Medication Initiative, or NAOMI, were released here on Oct. 17 and the results, researchers say, are "remarkable."
"Heroin-assisted treatment (HAT) is very safe when done properly," Dr. Martin Schechter, NAOMI's principal investigator, said at a news conference held to announce the findings. "Our results show it to be very effective."
The study is the latest effort made by a city with a history of employing often counterintuitive methods of tackling its drug problem. But while advocates tout the study's results, critics say the efforts amount to nothing more than a band-aid solution and a dangerous step toward legalizing drugs.
Fluctuating levels of local and federal support could either undergird or derail the effort here, and, with heroin demand increasing worldwide, it's a debate other nations are monitoring.
How does the treatment work?
HAT targets chronic addicts who have repeatedly tried but failed to kick the addiction that consumes their lives and devours taxpayer dollars through hospital trips and policing costs.
Instead, they are given controlled doses of heroin in a supervised clinic.
Researchers believed it would allow addicts to reduce their overall drug use, participate in less crime, and stay in treatment longer.
"This is a group, frankly, that society has written off as being beyond help," says Dr. Schechter, the director of the University of British Columbia's School of Population and Public Health.
Vincent, the drug user, says that he tried to quit heroin seven or eight times before entering the NAOMI study.
But he was always pulled back by the persistent cravings that left him ill.
"It's not something that I would wish on anybody," says Vincent.
With doses of heroin given three times a day at the clinic, Vincent stopped spending his days and nights trawling for his next hit.
For the first time in years, he found part-time work, unloading shipping containers down at the city's port.
"I was actually able to live a normal life," says Vincent.
A majority of participants had comparable results, NAOMI researchers found.
After 12 months in the study, illicit heroin use fell by almost 70 percent.
The number of days participants said they spent being involved in "illegal activity" was halved, as was the reported amount of money spent on drugs.
And 88 percent of those treated with heroin remained in treatment for at least one year.
In a climate where the thought of prescribing heroin to addicts might make the federal government queasy, proponents still see offering the drug in a range of treatment programs as a realistic option.
"Many people believe that we need a different approach," says Vancouver Mayor Sam Sullivan, who wants to see a clinic set up "tomorrow."
Vancouver is home to a concentrated and very visible addiction problem that has shamed and confounded successive governments.
One local advocacy group estimates there are 5,000 injection drug users living in the 12-block neighborhood locals used to call skid row: the Downtown Eastside.
And with Vancouver set to become a specimen under the international microscope of the 2010 Winter Olympics, there is an added urgency to address the problem.
"I think that once the citizens realize how much crime is going down, how much the load on our health services is going down, how much cheaper it is for everyone, that there's going to be a demand for this kind of program," Mr. Sullivan says.
Critics decry slippery slope
Yet others see the study's results as another wobbly step in the wrong direction.
"These guys just don't get it. Drug addicts need the cure, not the poison."
Mr. Arsenault said he agrees with addiction specialists that a small group of addicts will not quit drugs. But he argues the focus should instead be on increasing treatment options for all drug users, not prescribing drugs to the chronic abusers.
"What they're doing is they want to legalize drugs, when there's not enough treatment centers available," Arsenault says. "That's totally backwards.
"You don't start there, substituting one drug for another to keep them chemically addled in the corner," he says.
But the study's researchers remain confident in their findings.
"Based on the evidence," says Schechter, "we could apply and we will apply to have heroin licensed."