The report, released Thursday, also found that suicide rates are higher here than in some other developed nations.
Among those 15 and over who provide care to a family member with a long-term health condition, almost 17 per cent reported "very high" levels of stress, the report found.
The problem is expected to worsen due to increasing rates of dementia and other chronic illnesses, which is why caregiving is among four of 13 mental-health indicators deemed areas of "significant concern" by the commission.
So too are suicide rates, intentional self-harm among college students and mental health recovery.
Nearly 20 per cent of university students said they had engaged in self-harm, the study found.
The commission also determined that in 2011, almost 11 out of every 100,000 people — or 3,728 Canadians — killed themselves. The suicide rate, while stable over time, is higher than in some other G8 countries.
"There are known strategies that work to prevent suicide; other countries are doing it, like the United Kingdom," Jennifer Vornbrock, a commission official, told a news conference.
Canada should follow suit and invest in suicide prevention, she said.
The commission said it hopes the indicators will be used to develop broad strategies to improve mental health.
David Goldbloom, chair of the commission, said some of the indicators "raise significant concerns or indicate that we are moving in the wrong direction. ... We can take little comfort from many of them."
Vornbrock said she hopes the report will underline the need to take mental health more seriously.
She called mental health "the poor cousin of the poor cousin of the health-care system."
"We would like to see that mental health is prioritized amongst all the health spending, all the health-care priorities."
The federal government created the Mental Health Commission of Canada in 2007. The organization, funded by Health Canada, operates at arm's length and has a 10-year mandate.
By April, the commission will provide details on close to 60 indicators involving children, youth, adults and seniors in a variety of settings.
Thursday's study also found that more than 30 per cent of Canada Pension Plan disability claims relate to mental health. That figure has steadily increased since 2004 and is higher than disability claims for other health reasons.
The Conservative government has been under fire for months for a growing backlog of 11,000 social security appeal cases, most involving people denied Canada Pension Plan disability benefits.
The commission says there could be a silver lining to the data showing so many CPP disability claims are mental-health related.
"It is possible that the increase does mean that there is more acceptance and recognition, despite the backlog, that mental health claims are legitimate and must be supported," said Elliot Goldner, a University of Toronto psychiatrist and researcher and former commission official.
Chris Simpson, president of the Canadian Medical Association, praised the report.
"The use of health indicators for mental health surveillance has been critically lacking," he said in a statement.
The commission's work "will provide a more comprehensive understanding of the issues in this area," he added.
Liberal MP Hedy Fry called the report an indictment of the federal government.
"The Mental Health Commission of Canada has been calling very loudly for an integrated approach on mental health, and they have not been paid attention to," she said. "That says so much about how this government continues to treat its most vulnerable people."
Follow Lee-Anne Goodman on Twitter @leeanne25