The South West has among the highest rates of dementia in England, according to new figures.
The Alzheimer's Research Trust says Torbay has the highest prevalence of dementia at 2.0%, with Devon fifth at 1.67%.
In Devon, Cornwall, Somerset and Dorset the cost of care and health services is more than a billion pounds a year.
The trust says very little money is being invested in research into the condition.
Its figures show nearly 40,000 people in the South West have the disease. Nationally, the figure is 820,000.
Ian Sherriff from the South West Forum of the Alzheimers Society described the figures as a "tidal wave coming up the beach".
In the trust's Dementia 2010 report, it says the disease costs the UK twice as much as cancer, three times as much as heart disease and four times as much as strokes and claims, on present trends, the UK's approach to managing dementia is unsustainable.
Carers are also calling on the government for more research to cure and treat the disease.
Pat Criddle from Exeter, Devon, has cared for her husband Roger since he was diagnosed with vascular dementia 11 years ago, at the age of 53.
"It's very difficult. We were looking forward to retirement together, but it won't happen - life's on hold," she told BBC News.
"It's a lonely existence because you haven't got someone to share your problems with.
"They have to look more into research because obviously there's going to be a lot more people in the future with the illness."
Care Services Minister Phil Hope said the government fully recognised the importance of dementia research and by 2011 it would be investing nearly £1bn in health research.
He said in a statement: "This money is awarded to the best quality research for any health condition, including dementia.
"Dementia is one of the most important issues we face as the population ages and I want to see an increase in the volume, quality and impact of dementia research."