Doctors currently use simple mental agility tests to screen for the condition, but experts from Northwestern University in Chicago believe a face recognition test should be used too.
The research showed that people with early onset primary progressive aphasia (PPA), a rare form of dementia, struggled to identify black and white prints of 20 famous people, including Albert Einstein and Martin Luther King.
Nuances and differences in dementia
Compared with 27 dementia-free volunteers, the 30 participants with PPA scored poorly on the facial recognition test: 93% of the 'healthy' group were able to successfully name all of the famous faces, but just 46% of the PPA patients could.
Lead author Tamar Gefen said: "Facial recognition could be incorporated into a battery of tests for dementia. There are a lot of nuances and differences in dementia so it is good to use different tests. Doctors already screen by asking questions such as 'What month and season is it?'
"[However,] more research needs to be done to figure out whether this test distinguishes all people with dementia from people without dementia or whether it distinguishes only people with one particular type of early-onset dementia from people without dementia.”
Moving results towards better diagnosis
Brain scans of the participants with PPA revealed loss of brain tissue in areas that deal with recognising faces and Gefen believes the test could be adapted based on the participants' age and background.
Commenting on the findings, Dr Marie Janson from Alzheimer's Research UK said: "It's important to be able to give an accurate diagnosis for people with dementia so they can gain access to the right care and treatments, but the different forms of dementia can be difficult to identify.
"Studies such as this could increase our understanding of the way the brain is affected by different forms of dementia, but we must invest in research if results like these are to be used to move towards better diagnosis."