Lt. Col. Stephane Grenier says he returned to Canada in 1995 "a slightly different person" after a 10-month tour in Rwanda where he witnessed shocking genocide. (CBC)

Canada's chief of defence kicked off an awareness campaign Thursday to try to lessen the stigma attached to mental illness in the military and encourage troubled soldiers to come forward.

Gen. Walter Natynczyk officially launched the "all right to hurt" campaign in Ottawa following intense internal debate in the wake of last week's House of Commons defence committee report.

It recommended that military brass provide leadership on raising awareness on the issue. It also recommended an audit to identify gaps in the mental-health system as well as better training for senior officers on how to spot soldiers with stress issues.

During the campaign, members of the Forces will publicly share their struggles with mental illness, which the military refers to as "operational stress injury." The term is meant to encompass depression and anxiety, as well as heavy drinking and illicit drug use.

After a 10-month tour in Rwanda where he witnessed shocking genocide, Lt. Col. Stephane Grenier returned to Canada in 1995 "a slightly different person," he told CBC in an interview.

"What happened to us in Rwanda really shocked my own belief systems, my own values, my own morals."

The military tends to be a "very macho, very stoic culture," so getting support within that workplace from superiors is key to recovery, which is what happened for him, Grenier said.

"That's what this campaign is all about — to change that culture of ours and make it acceptable that the mind can also be injured."

In the military, mental illness has four main triggers: trauma, grief, fatigue and moral injury, Grenier said.

"The moral piece is huge because it's really when your personal values come in conflict with your experiences overseas" that suffering happens.

As many as 20 per cent of Canadian soldiers serving in Afghanistan are likely to suffer from mental illness upon their return home, he added.

"As much as clinicians are part of the solution, leaders at all levels [from] privates all the way up to the chief of defence staff, including myself, we're part of the solution as well."