Campaigners have welcomed an official report that criticises the government and health chiefs for not doing enough to tackle the crisis in dementia care.
The National Audit Office (NAO) said the UK has fallen behind other European countries when it comes to early diagnosis and giving patients effective drugs.
The study is now calling on the government to show leadership and accuses the Department of Health of failing to make dementia a priority.
About 560,000 people in England are estimated to suffer from dementia, but that figure is expected to rise to 750,000 by 2020.
The report claims only a third to half of people with the condition ever receive a formal diagnosis.
There is also a "widely held perception" among GPs and the public that hardly anything can be done, it added.
Less than a third (31%) of GPs questioned by the NAO feel they have had the correct training to diagnose the disease, while 70% said they do not have enough time to spend with people suffering dementia.
Rebecca Wood chief executive of the Alzheimer's Research Trust, said: "Hopefully this criticism from the National Audit Office will lead to the Government finally getting its act together on tackling dementia in Britain.
"The report unambiguously laments the Department of Health and NHS's historical failure to give dementia the funding it deserves.
"It clearly states that too few people are being diagnosed or being diagnosed early enough, and that things are only going to get worse in the years to come as the population grows older.
"Yet the government continues to stick its head in the sand when it comes to funding dementia care and research for better diagnosis and treatments."