Social media hype driving misuse of Alzheimer’s blood tests, researchers warn

Researchers warn social media may be driving healthy people to take Alzheimer’s blood tests, risking anxiety over markers that may never lead to dementia.

Blood-based biomarker tests such as p-tau217 and p-tau181 detect biological signs associated with Alzheimer’s disease, a progressive brain disorder and the leading cause of dementia.

The tests look for abnormal proteins linked to changes in the brain. They can be quicker and more accessible than brain imaging or lumbar punctures.

Neurological bodies including the Alzheimer’s Association advise that such tests should not be used to screen healthy people without symptoms.

The tests should also not be used alone to diagnose Alzheimer’s disease and need to be considered alongside other medical assessments.

Because they can detect biological changes associated with Alzheimer’s before symptoms develop, someone may test positive for disease markers but never go on to develop clinical symptoms of dementia.

Dr Jenna Smith, from the University of Sydney’s school of public health, told The Guardian that laboratories, influencers and doctors around the world have promoted the tests on social media.

Smith and her colleagues analysed 188 Facebook, Instagram and TikTok posts mentioning Alzheimer’s or dementia and blood tests.

The accounts had a combined global audience of more than 114m followers.

Smith said about 10 per cent of the posts came from doctors claiming the tests could be useful for asymptomatic screening, with most of those doctors based in the US.

“Some of these doctors had pretty clear financial interests,” Smith said.

“But it isn’t all doom and gloom. Some doctors were sharing information about these new blood tests with longer videos and covered the nuance that this issue deserves.

“Some also specifically drew attention to the limitations and potential harms.”

The findings were published in the Journal of the American Geriatrics Society.

More than one-third of the posts promoted the tests for people without symptoms. Accounts with explicit financial interests were more than three times as likely to do so.

“The main potential harms are being unnecessarily diagnosed and not having a clear pathway for what to do next,” Smith said.

“Healthy people who undergo these tests could be diagnosed with Alzheimer’s disease but not go on to develop dementia. It is also not clear what to do next after testing positive.

“Research on treatments has been done in people with mild cognitive impairment or dementia, so we don’t know if they work for healthy people who test positive.”