By Adam Brimelow
Health correspondent, BBC News
There are 700,000 people in England with dementia
More than 30 leading scientists have backed a call for a three-fold increase in funding for research into dementia in the UK.
They have signed an open letter, timed to coincide with a government-hosted dementia research summit in London.
The experts have urged the government in England to end "years of underfunding" for research into the debilitating disease.
But ministers said they were already investing strongly in research.
The London summit will bring together scientists, doctors, carers and people with dementia.
It will set out to identify where support is needed most, and to help ensure that dementia research gets its fair share of funding.
Seven hundred thousand people in the UK now live with dementia, and the figure is going up fast.
It is estimated that the cost of treating and caring for people with dementia is £17bn a year - more than the cost of heart disease, stroke and cancer combined.
However, research into cancer received far more government funding.
Professor Nick Fox, from University College London, said the support for cancer research has shown what might be achieved with dementia.
He said: "We've seen the benefits in other areas of improved research, improved care, and moving away from very non-specific diagnoses of cancer to very specific molecularly targeted treatments for specific cancers which have clear diagnostic fingerprints. The same should happen in dementia."
Professor Julie Williams, chief scientific advisor to the Alzheimer's Research Trust, agreed that a funding boost could pay handsome dividends.
She said: "In the last two years we have been able to do experiments we only dreamt of years ago.
"We are able to capitalise on new technologies and look at every single gene in the human genome in thousands of people.
"And with this we will get new information on the triggers of Alzheimer's Disease."
But Professor Clive Ballard, director of research at the Alzheimer's Society, said a lack of investment had created a time-lag in turning scientific advances into new treatments.
He said the number of trials needs to increase tenfold to speed up the rate of discovery.
"Research doesn't turn new treatments round in five minutes.
"It does take five to 10 years even with the right investment to turn research into new therapies, and new ways of preventing disease. So it's now we need to invest in it."
Researchers are clearly excited about the summit, but also concerned it could simply turn out to be a talking shop.
Professor John Hardy, a scientific adviser to the Alzheimer's research trust said hopes had been raised before.
"I'm concerned that what will happen is that they will come up with the idea that they should have a focus group of some description to come up with a plan that will take a year or 18 months to report.
"They are going to hope in that 18 months that everyone will have lost interest so they can quietly do nothing. That's usually what they do."
In their open letter, the scientists call for a threefold increase in government funding for dementia research; taking it to £96m a year.
The government in England said it was already investing strongly in dementia research.
Phil Hope, the Minister of State for Care Services, said: "By 2011, the total National Institute for Health Research budget for all health science will be nearly £1bn.
"We now need to increase the number of successful dementia research proposals to access to this investment."