Most people with dementia in the US are unaware of their condition. A population-based study in Texas has now found that four out of five people with probable dementia have not received a formal diagnosis and are not being treated for cognitive decline.

That's not for a lack of healthcare, either. In the new study, less than 7 percent of participants with probable dementia had no primary care provider, and there was no link between a lack of primary care and a lack of diagnosis.

In other words, most people over the age of 65 with cognitive decline were routinely seeing their doctor, but they were not receiving a diagnosis.