Researchers have raised concerns about the growing use of blood-based tests for Alzheimer’s disease being promoted on social media to healthy individuals, warning this trend may lead to unnecessary anxiety and potential harm. These tests detect biological markers—such as abnormal levels of p-tau217 and p-tau181 proteins—that are linked to changes in the brain associated with Alzheimer’s, a progressive neurodegenerative disorder and the leading cause of dementia.
Blood biomarker tests offer advantages over traditional methods like brain imaging or lumbar punctures, as they are typically quicker and less invasive. However, leading neurological organizations, including the Alzheimer’s Association, advise that such tests should not be used as screening tools for people without symptoms. Experts emphasize that these tests cannot diagnose Alzheimer’s on their own and should only be interpreted alongside comprehensive clinical assessments.
Dr. Jenna Smith of the University of Sydney’s School of Public Health and her colleagues analyzed 188 social media posts about Alzheimer’s blood tests, originating from accounts reaching a combined audience of more than 114 million followers worldwide. They found that over one-third of these posts promoted the tests for asymptomatic individuals. Around 10% of the posts, mainly from doctors—predominantly in the United States—endorsed the use of these tests for screening despite ongoing debate over their appropriateness. The study highlighted that accounts with financial interests in the tests were more likely to promote their use among healthy people.
“The main potential harms are being unnecessarily diagnosed and not having a clear pathway for what to do next,” Smith said. She noted that a positive test result for Alzheimer’s biomarkers in a healthy person does not guarantee that dementia will develop, and there remains uncertainty about how to manage or treat such cases. Current treatments have been tested in people with mild cognitive impairment or diagnosed dementia, but their effectiveness for asymptomatic individuals who test positive is unknown. Concerns also include the psychological impact of testing, financial costs, and possible implications for insurance.
Professor Susan Kurrle, president of the Australian and New Zealand Society for Geriatric Medicine, stressed that Alzheimer’s blood tests should only be ordered by doctors under specific conditions where there is a high suspicion of early disease. “It is most definitely not a screening test,” she said, warning that unnecessary and expensive testing can be problematic. In Australia, these tests cost up to AUD 400 when ordered through a physician and are not covered by Medicare, while direct-to-consumer options online can cost upwards of AUD 600, sometimes without proper pre-test screening.
Kurrle also cautioned that false positives might cause healthy individuals to believe they will inevitably develop dementia, whereas negative results could foster false reassurance and neglect of modifiable risk factors such as physical inactivity, vascular health, hearing, or vision loss.
The researchers’ findings were published recently in the Journal of the American Geriatrics Society, prompting calls for clearer guidelines and public education to prevent the misuse of Alzheimer’s biomarker tests on social media platforms.