​Marijuana has harmful effects and there's no proof it helps with post-traumatic stress disorder, says Veterans Affairs Minister Erin O'Toole.

"There's a number of voices out there suggesting it's a treatment for PTSD; there's no clinical support for that," O'Toole said Wednesday. "Certainly, there is some support for symptom relief for chronic pain or anxiety, some symptoms."

He spoke after a CBC News investigation revealed that nearly two-thirds of the money the federal government spent on medical marijuana last year went to veterans in Atlantic Canada — a region with about 14 per cent of the total number of veterans.

According to Veterans Affairs Canada, the federal department spent $5.2 million on medical marijuana for veterans in the last fiscal year. Of that, almost $3.4 million — or 65 per cent — went to veterans in Atlantic Canada.

Fabian Henry, a former Canadian Forces member from New Brunswick, takes responsibility for helping to introduce medical marijuana to East Coast veterans suffering from post-traumatic stress disorder.

His company, Marijuana for Trauma, connects veterans with physicians willing to authorize medical cannabis. The organization has helped hundreds of vets fill out forms for medical pot reimbursement from Veterans Affairs Canada in the year since it's been open.

They have to find ways to manage their own symptoms when VAC is failing them. - Frank Valeriote

O'Toole said Veterans Affairs has "been working with health-care professionals to make sure that if, in some cases, medical marijuana can help a veteran, that's been there for them." But he said pot can have harmful effects.

Throughout CBC's look at the medical marijuana reimbursement numbers for veterans in Atlantic Canada, emails from a department spokesperson often ended with a reminder that "marijuana is not an approved drug or medicine in Canada."

"The Government of Canada does not endorse the use of marijuana, but the courts have required reasonable access to a legal source of marijuana when authorized by a physician," one such email said.

Veterans Affairs wants physicians to look carefully at the needs of the veteran, said O'Toole.

"Certainly there's commercial entities and a number of parties involved now with the changing landscape since the court decision several years ago on medical marijuana," he said. "But we need this to be a decision of the health-care provider for the veteran."

'Serious mental challenges'

NDP veterans affairs critic Peter Stoffer said he didn't know why so many vets in his home region are turning to marijuana.

"I can only assume it's because licensed physicians are saying that for folks going through these very serious mental challenges, that to alleviate their concerns, medical marijuana would be a good thing to have," he said.

On Tuesday, Liberal veterans affairs critic Frank Valeriote said vets are treating post-traumatic stress disorder symptoms with medical cannabis because the government isn't doing enough.

"They have to find ways to manage their own symptoms where VAC, Veterans Affairs Canada, is failing them," he said.

But Stoffer said he had to give O'Toole credit for "starting to realize that the cookie-cutter approach to mental health awareness and wellness is not working" for conditions such as PTSD.

Every situation has to be dealt with on an individual basis and that's costly, he said.

"Obviously, in this case some of that treatment base is medical marijuana."

O'Toole said Canada and other countries are looking at medical marijuana treatment to "make sure we have data and clinical support."

"So that veterans know: is this actually helping their underlying mental health condition?"