OTTAWA -- The Conservative government is being called upon to develop a national dementia strategy.

Both the Canadian Medical Association and the opposition NDP say Canada should join 13 other countries that already have strategies to deal with the fast-growing problem of Alzheimer's and similar diseases.

Chris Simpson, the association's president-elect, says a plan would help Canada's over-taxed health-care system cope with as many as 750,000 patients suffering from Alzheimer's and other forms of dementia.

It's estimated that dementia costs Canadian taxpayers $33 billion a year in both direct health-care costs and the lost income of family members who are forced to act as caregivers.

The NDP is also calling on the government to back proposed legislation that would establish a national dementia plan, saying Canadians deserve better.

Matt Dineen, whose partner was recently diagnosed with dementia in her early 40s, has written to Health Minister Rona Ambrose urging a national strategy.

The call for action comes on the eve of a G8 summit on dementia taking place in London. Simpson says Canada has the "dubious distinction" of being the only G8 country without a national dementia strategy.

In a statement, Ambrose defended the government's record on tackling dementia. She said Canada is a leader in the area of dementia research and added the government is "committed to taking further action to address the growing problem of dementia."