Just because you’ve had a diagnosis of Alzheimer’s doesn’t mean you’ll be able to tell if you’re at risk of developing dementia.
It’s been known for years that symptoms can be a warning sign of the disease, but new research has found that the symptoms are less reliable than previous studies have suggested.
“We have the first evidence to suggest that the signs of dementia are less reliably observed in people who have no prior history of dementia, which may explain why this new study didn’t find any significant difference in dementia diagnosis between people who were tested as early as possible and those who were diagnosed with Alzheimer’s disease,” Professor Simon Lewis, from the University of Melbourne’s School of Gerontology, said in a statement.
“It may well be that some people are diagnosed early and may develop dementia much later than expected.”
He and his colleagues, from Imperial College London, compared people with and without Alzheimer’s symptoms to 2,300 people in Australia.
They looked at more than 11,000 cognitive tests, including memory and thinking skills.
They found that while dementia diagnoses were reliable, they were still highly variable between people.
They found that people with more severe dementia were more likely to be diagnosed than those with milder dementia.
This could mean that people who suffer from Alzheimer’s can be more vulnerable to developing the disease.
The researchers also looked at other factors that may affect how accurately people can diagnose dementia.
People with more frequent comorbidities, such as asthma, had lower rates of dementia diagnosis.
They also found that individuals with more extensive family history of the disorder were more often diagnosed with dementia than those who did not.
And individuals with higher levels of education, as well as those with lower levels of social class, were more frequently diagnosed with the disease than those without.
This may explain how a person with a diagnosis may have been diagnosed earlier, and be more likely not to suffer the disease later.
Professor Lewis said more research was needed to find out exactly how different people with different levels of dementia may react differently to the disease symptoms.
He added: “The underlying mechanism behind this difference is that our memories are less accurate than our mental images, and this may explain the variation in dementia diagnoses.”
The study was published in the journal Neurology.
It is not known exactly how much of this variation could be attributed to people being more likely than others to be tested early.
Previous studies have shown that people in older age groups are more likely still to have dementia than younger people.
For example, in the US, people who are diagnosed as adults with Alzheimer, or people with a previous diagnosis of dementia or a family history, are much more likely in later life to have a diagnosis, the BBC reported.
There is some evidence that the risk of dementia increases with time, so it is likely that people diagnosed with a first diagnosis of the condition are more at risk for developing dementia in later years.