Canadian soldiers patrol an area in the Dand district of southern Afghanistan in June 2009. New figures from the military say suicides among active troops were higher than in the previous year. (Colin Perkel/Canadian Press)

More Canadian soldiers killed themselves in 2008 than the year before, but the overall suicide rate has remained steady throughout the war in Afghanistan, says a military study.

Newly released Defence Department documents show 15 active-duty members of the military took their own lives last year, a rate of 23 per 100,000. In 2007 there were 11 confirmed suicides.

The average rate of suicide over the three years Canadian troops have been involved in the heaviest combat in Afghanistan — from 2005 to 2008 — was 17.9 per 100,000, the study found.

The average suicide rate for all of Canada was 11.6 per 100,000 in 2005, the most recent year for which data from Statistics Canada is available.

The figures come as public awareness increases about the mental health of soldiers in both Canada and the United States.

The death of Canadian Maj. Michelle Mendes in Afghanistan in her living quarters on April 23 led to speculation on health problems or an accident, or possibly suicide, as a cause of death, bringing the issue of soldier stress to the forefront. A probe into Mendes's death has yet to release its findings.

In June, Chief of the Defence Staff Gen. Walt Natynczyk launched a Canadian Forces mental health awareness campaign in an effort to provide support to troops for mental health issues.

Shorter tour of duties

Canada's top military doctor, Commodore Hans Jung, said that when focusing on three-year averages, Canadians appeared to be faring better than the U.S. when it comes to dealing with the stresses of war.

He said the shorter six-month tours of Canadian soldiers, compared with the nine- to 15-month tours for American soldiers, have helped Canadian soldiers deal better with the stresses of war.

"That tour length is a huge issue," said Jung.

There were 128 confirmed U.S. army suicides in 2008 — a rate of 20.2 deaths per 100,000.

The Canadian military figures don't track suicide rates among reservists, a group who are filling an increasing number of positions in Kandahar.

Liberal MP Dan McTeague said the lack of reservist data is "a glaring omission."

"One would think, considering the structure of the Armed Forces and how important reservists are to operations such as Afghanistan, that there would be particular [attention] paid to their situation," he said.

Mounties suffering post-traumatic stress

Soldiers aren't the only men and women in stressful, front-line occupations that are suffering from mental health issues.

RCMP statistics obtained by CBC News reveal that a growing number of Mounties are on disability leave for post-traumatic stress disorder.

Ten officers claimed partial or full disability for PTSD in 1999-2000, compared with 162 officers in 2007-08, the last year for which complete figures were available, according to figures from the RCMP's statistics directorate.

The number of officers on disability for PTSD spiked as high as 208 in 2005-06.

With files from The Canadian Press