Alzheimer's campaigners are calling for a four-fold increase in spending on medical research into dementia as a global report predicts the cost of treating the disease will soar in coming years.

The World Alzheimer Report estimates the worldwide cost of dementia will reach $US604 billion ($631 billion) this year, or more than 1 per cent of global GDP, and will likely skyrocket as patient numbers triple by 2050.

Alzheimer's Australia says the price tag in this country could be substantially reduced if the Government injected even just a small proportion of the cost of dealing with the disease into medical research.

The group's chief executive, Glenn Rees, says Australia spends just $12 million a year on dementia research through the National Health and Medical Research Council, compared with $130 million a year on cancer research.

"I don't begrudge cancer their money at all; it's a tragic and awful disease. But if you look at the numbers of people with dementia, the costs of dementia, the disability burden it brings with it, then the investment in dementia research is totally disproportionate," he said.

"We've been saying to the Government that if they spend 1 per cent of the cost of dementia to the healthcare system a year in Australia on dementia research, that would be a start. So that would be $50 million a year."

Mr Rees says while urgent action is needed, the World Alzheimer Report did praise the actions of the Government, with Australia just one of a handful of countries with a national Alzheimer's strategy.

"Australia can take a lot of pride in the fact that we were the first country in the world to make dementia a health priority in the 2005 budget with some additional funding," he said.

"Have we got it right? No. There are some important gaps in primary care, in delayed diagnosis.

"Hospitals remain very unfriendly places for people with cognitive impairment, and dementia hasn't been embraced at all in preventative health policies."

Mr Rees says because 60 to 70 per cent of the people with Alzheimer's in advanced economies live within the community, it is essential their carers get more support.

That includes better respite care, to give the carer a break and to give the patient access to social activities and support.

One of the authors of the World Alzheimer Report, Professor Martin Prince of King's College in London, says the cost of care is going to soar in the years ahead with the number of sufferers tipped to almost double every 20 years.

He says there will be 115 million dementia sufferers worldwide by 2050, more than three times the 35.5 million people who currently suffer.

"If [dementia] were a country, it would be the world's 18th largest economy. These are huge sums of money and governments, we feel, need to take action now," he said.

"What we're going to see as time goes by is, first of all, increased demand for care; secondly, more expensive and more effective interventions for people with dementia, in particular, drug treatments that potentially could alter the course of the disease; and finally we're going to see a shift from the cost of care from family carers, which is unpaid, towards paid care."

Despite decades of research, scientists have failed to develop drugs that can halt or reverse dementia.

That is despite clinical trials that are underway into about 100 compounds that have shown some promise.