NHS figures show that more than 200,000 people aged 65 and over in England have the neurological condition but have not had a diagnosis.
Estimates for the country’s NHS Clinical Commissioning Group (CCG) areas show that on average, some 68.3 per cent of people with dementia have been diagnosed.
But there are wide variations in diagnosis rates, linked to the proportion of elderly people in the population in different parts of the country.
And concerns have been raised that people in rural communities could be less likely to seek help with the onset of the condition.
In Bradford, about 82 per cent of people with dementia have been given a diagnosis, compared to just 58.1 per cent in Scarborough and Ryedale and 60.7 per cent in the Vale of York area. Memory loss, anxiety, depression and mood swings are among symptoms off the progressive illness, which includes Alzheimer’s disease.
Calls have been made for action to improve diagnosis rates – and people are being urged to seek medical help if they or a family member start to experience symptoms.
Andrew Boaden, senior policy officer at the Alzheimer’s Society, said: “With the number of people with dementia set to reach one million by 2021, the Government and the NHS must do more to address this issue.”
Linda Haggie, Alzheimer’s Society operations manager for North Yorkshire, added: “Early diagnosis is important to allow people with dementia to understand the condition, how to manage it, how they can maintain independence for as long as possible and opens up access to treatments that are most effective in the early stages of the condition.
“A diagnosis also means people can access support services and means people have time to plan for the future.
“Alzheimer’s Society always encourages anyone who is concerned about their memory to visit their doctor and ask them to check out their symptoms.
“Without a diagnosis people cannot receive the support, information and treatment they need to live well with dementia.”
The Government pledged to improve diagnosis rates and support for families as part of its Dementia Challenge 2020 plan. The Department of Health and Social Care said the national diagnosis rate had risen from 42 per cent in 2010-11, and more people were being diagnosed than ever before.
A spokeswoman for the department said: “This government is committed to making this the best country in the world for dementia care, support, research and awareness.
A timely diagnosis of dementia is vital to ensuring that individuals with the condition, their families and carers, can access the advice, information, care and support that can help them to live well with the condition and remain independent for as long as possible.”
Leeds City Council said the city’s diagnosis rate for dementia was almost 75 per cent, compared to just over 50 per cent five years ago.
Diagnosis rates for the city’s three NHS areas were higher than the national average.
The council’s director of adults and health, Cath Roff, said: “We know dementia is an important issue for Leeds, as it is across the country.
“Diagnosis rates have continued to improve in recent years and Leeds does well.
“This helps ensure support can be put in place sooner, and public awareness of symptoms also helps in this. While it is helpful to have a formal diagnosis, the lack of it does not stop people getting support as we base our assessment on presenting needs.
“Also in Leeds we’re putting in place a range of refreshed services for people with dementia and their families, with new complex needs centres which help more people to live better lives with dementia by offering support that reflects changing expectations and needs.”
Figures for December show north Leeds had as a 69.3 per cent diagnosis rate, compared to 73.9 per cent in west Leeds and 80.8 per cent in the Leeds south and east CCG area.