More than 250,000 dementia patients could miss out on new treatments for the disease because they do not have a formal diagnosis, according to government figures. NHS data published for the first time shows the prevalence of different types of dementia with which people in England have been diagnosed. Dementia is an umbrella term for many different conditions, affecting more than 55 million people worldwide. The NHS primary care dementia figures, released on Thursday, estimate that there are about 708,000 people over 65 with dementia in England, but only about 450,000 have a recorded diagnosis. That means that more than 250,000 are missing out on potential new treatments. The estimate comprises the number of people thought to have dementia, based on age, sex and other factors. This week, health regulators were urged to approve two new game-changing dementia drugs, after a landmark study confirmed that donanemab slowed cognitive decline in Alzheimer’s patients by 35%, while last year, a second drug, lecanemab, was found to reduce the rate by 27%. According to the National Institute of Clinical Excellence, 50-70% of people with dementia will have Alzheimer’s disease. But more than a third of Alzheimer’s patients will be unable to access them, Thursday’s data shows, because they do not have a recorded diagnosis. The new drugs are only suitable for those with a specific diagnosis of Alzheimer’s disease, with the confirmed presence of amyloid protein in the brain or cerebrospinal fluid. James White, the head of national influencing at Alzheimer’s Society, said: “Dementia is the UK’s biggest killer, and with two new potentially life-changing drugs for Alzheimer’s disease in the pipeline, there has never been a bigger incentive to ramp up dementia diagnosis. “This data shows there are at least 203,541 people with a diagnosis who could benefit from these treatments, but there are many others who either have a generic diagnosis or no diagnosis at all. “We can’t end up in a situation where there are new drugs being approved but people in the UK can’t benefit from them because they have not had access to an early and accurate diagnosis. “The government must improve diagnosis rates through targeted funding to allow people living with dementia to access these breakthrough treatments and ensure our health system is ready to deliver the drugs when they come.” The new NHS figures show how many patients have Alzheimer’s, vascular, mixed and other dementias, which includes those whose specific form of dementia is undiagnosed. The data is being released in response to a letter that nine dementia charities sent to the health secretary in April. Previously, this data was not collected or published by NHS England. It shows more than 78,000 people have vascular dementia and just over 24,000 have more than one form of dementia. The figures also list 162,819 people with “other” dementia, who either have a different type of dementia or do not know what form of it they have. There are additionally 16,024 people aged 64 and under with a dementia diagnosis. Responding to the figures, charities welcomed the new data, but called on the NHS to publish a more detailed breakdown, given that there are more than 200 forms of dementia. Andy Pike, head of policy, campaigns and public affairs at Dementia UK, said: “We need to have data for more than just four categories. Those affected by rarer subtypes are at risk of being excluded from dementia policy and care plans if we do not have the full picture of people living with a diagnosis of dementia in the UK.” Laura Cockram, head of policy and campaigning at Parkinson’s UK, called on the NHS to provide figures on those with Lewy body dementia – the third most common form – under which Parkinson’s falls. She said: “People with Parkinson’s are up to six times more likely to develop dementia than the general population. As Parkinson’s diagnosis rates increase, so will related dementia rates, and the government has to be ready to meet the future health, social care and welfare needs of these people.” Tessa Gutteridge, chair of the Young Dementia Network, said: “Seventy per cent of people with young onset dementia will be consigned to the ‘other’ category if there are no requirements to report the vital detail of ‘type’. “This, along with the absence of age at diagnosis, will prolong the inequality experienced through poor recognition, unclear diagnosis routes and inadequate support.” An NHS England spokesperson said: “The NHS is publishing increasing amounts of data to give a more accurate picture of dementia rates, helping to improve care for people at a time when referrals to memory clinics are increasing. “NHS support for people affected by dementia continues to improve, including through providing personalised care packages, but catching it early makes the biggest difference, so if you or a family member think something is not quite right, please come forward to your GP as soon as possible.”