Overdose deaths in Vancouver's troubled Downtown Eastside have dropped by more than a third since the creation of Insite, the neighbourhood's supervised injection clinic, according to a study in the British medical journal The Lancet.

Researchers with the B.C. Centre for Excellence in HIV/AIDS studied the number of overdose deaths around the injection facility before and after its creation. Insite has operated since 2003 with exemptions from federal drug laws, first allowed by the former Liberal government.

The study, published Monday, found overdose fatalities have dropped 35 per cent, a number The Lancet calls "impressive."

The Insite supervised injection facility on Vancouver's Downtown Eastside provides an indoor space for addicts bring illegal drugs bought on the street and inject them under medical supervision. (CBC)

"Overdose death is such a tragic and horrific outcome, the fact that it's able to reduce overdose deaths, from a public health perspective, we're just thrilled," said Dr. Evan Wood, co-author of the study.

Overdose deaths fell elsewhere in Vancouver at the same time but by much less than in the area surrounding Insite, according to researchers from the B.C. Centre for Excellence in HIV/AIDS.

Heroin and cocaine addicts at Insite — the only sanctioned facility in North America for injection of illegal drugs — get medical supervision as they inject themselves with their own drugs, using clean needles. They are also offered addiction treatment programs.

The federal Conservatives want Insite shut down and tried to pull the plug in 2008, but the fight to keep the facility open went to B.C. Supreme Court, which ruled closing it would be unconstitutional.

Next month, the Supreme Court of Canada will hear the federal government's appeal of the decision.

The Lancet commentary accompanying the new study notes the issue is "politically fraught," adding supervised injection facilities "should be expanded to other affected sites in Canada, based on the life-saving impacts identified in Vancouver."