When $5.5 million was spent to erect barriers around Toronto's Bloor Street Viaduct to prevent suicides, many wondered whether it would really work. Now, researchers have the answer.

The Viaduct, which is a huge overpass in midtown Toronto that spans a highway, ravine and river, once had the unfortunate distinction of being the second most popular bridge for suicides in the world, after the Golden Gate Bridge in San Francisco. It's estimated that more than 400 people have leaped from the viaduct since it was built in 1918.

Then, in 2003, city planners decided to erect a barrier, dubbed the Luminous Veil, in an effort to deter jumpers.

So did suicide rates in Toronto drop? A team of psychiatry researchers at the University of Toronto and Sunnybrook Health Sciences Centre, set out to find out. They reviewed records at the Office of the Chief Coroner of Ontario from between 1993 to 2001, and then from July 2003 to June 2007, after the barriers went up.

And they found good news and bad news about the barrier.

"The overwhelming answer is ‘Oh yes, it works... at the Bloor Viaduct'," reports Dr. Anthony Levitt, chief psychiatrist at Sunnybrook.

Indeed, the researchers found suicides from the bridge fell from an average of 9.3 a year to zero a year. But when the researchers looked further, they found that the city's overall annual rate of suicide by jumping was almost unchanged: 56.4 per year before the barrier compared to 56.6 per year after.

As well, the number of suicides by jumping from bridges other than the Bloor Street Viaduct rose from 8.7 per year to 14.2 per year after the barrier was installed. The study is published in the July issue of the British Medical Journal (BMJ).

The study appears to prove what many had already suspected: that physical barriers alone are not enough to deter people intent on killing themselves.

"I think barriers are a piece of the puzzle but they are not the whole answer," says co-author Dr. Mark Sinyor.

"In order to really prevent suicides, you need programs that improve access to psychiatrists and other mental health workers, that improve the sense of hope. And barriers don't do that," he says.

Sinyor says it's unfortunate that while there is often funding for concrete restriction projects, mental health support programs remain chronically underfunded.

This is considered the first clear evidence that when a barrier is placed on one bridge, there can be a significant increase in suicide-by-jumping from other bridges in the area.

And it's an important message to city planners in San Francisco, who are planning to install a net below the Golden Gate Bridge: Barriers may simply move the problem elsewhere, unless officials deal with the underlying suffering that prompts suicides in the first place.

With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip