British stoicism is holding back older people from seeking treatment for Alzheimer's disease, research suggests.
Alzheimer's mainly affects elderly people
Britain has the longest average time between first symptoms being noticed and a diagnosis being made, a poll of six European countries showed.
The average across the countries was 18 months, but the UK figure was 32, global researchers Millward Brown said.
They said the UK delay reflected the reluctance of many elderly to make a fuss about symptoms and seek help.
Experts argue that treatment for Alzheimer's disease is most effective if begun at the earliest stages.
The survey looked at the UK, France, Germany, Spain, Italy and Poland.
Average time between first symptoms and diagnosis
Germany -10 months
Italy - 14 months
Spain - 17 months
Poland - 23 months
France - 24 months
UK - 32 months
It took the views of Alzheimer's patients themselves, their carers, family doctors and specialists, and health managers in charge of Alzheimer's disease services.
The survey found that almost half of the UK patients (49%) were not diagnosed until the moderate to severe stages of the illness, with 3% not being found until the severe stage when it is too late to try drug treatment.
Dr David Wilkinson, a consultant Old Age Psychiatrist from Southampton, said Alzheimer's specialists were beginning to see people in their 40s worried about slight forgetfulness, but older people with genuine symptoms were slow to consult doctors.
He said: "Traditional British stoicism is a public health problem in terms of Alzheimer's disease.
"I am seeing people in their 50s, some in their 40s, who are worried because they have mislaid their car keys.
"Some have got what I call memory neurosis, but we are not getting through to people who really need the help - those in their 70s.
"We are getting the message through about early treatment but in the wrong places. We have got to get the message through that older people are valuable."
Dr Wilkinson added: "Older people feel their symptoms are not a legitimate medical need.
"There are problems still in some areas with restrictions on the anti-dementia medicines, but a larger problem is that we need to be encouraging older people to come forward early."
He said the early symptoms of Alzheimer's, which is a common problem in the elderly, include memory loss, mood changes and communication difficulties.
Neil Hunt, of the Alzheimer's Society, said: "There is clearly still a lot of stigma and misunderstanding attached to dementia.
"We need to let people know about the many services and drug treatments available for people with dementia to avoid delays like these."
Carers gave a range of reasons for waiting to see a doctor, despite noticing possible symptoms of Alzheimer's disease in their loved one.
More than half, 58%, said they believed at first that the symptoms were part of normal ageing.
However, 64% admitted that in retrospect they were in denial about a loved one having Alzheimer's disease.
And in the UK, 72% of the carers said fear about Alzheimer's disease kept people from speaking to their doctor about it - a far higher number than seen in the other countries.
Eight out ten carers felt the government was not investing enough to tackle Alzheimer's.
This feeling was echoed by 70 of the 100 UK doctors who took part in the survey.
The research, commissioned by two drug companies, is based on 2,550 interviews.