Concerns Over Alzheimer’s Blood Tests Misleading Healthy Individuals

Researchers have raised alarms about the potential for social media to mislead healthy individuals into getting Alzheimer’s blood tests, leading to unnecessary anxiety about biological markers that might not result in dementia.

Blood tests like p-tau217 and p-tau181 are designed to identify biological indicators of Alzheimer’s disease, which is a progressive condition and the foremost cause of dementia. These tests search for abnormal proteins, which may signal changes in the brain linked to Alzheimer’s. There’s been a lot of optimism surrounding these tests since they tend to be quicker and more accessible compared to traditional methods such as brain scans or lumbar punctures.

Global authorities in neurology, including the Alzheimer’s Association, agree that these tests should not be administered to healthy individuals without symptoms. They emphasize that blood tests alone are inadequate for diagnosing Alzheimer’s and must be used alongside other medical evaluations. Since these tests can detect signs of Alzheimer’s early on, someone might test positive for biological markers but never actually develop the clinical symptoms of dementia.

Dr. Jenna Smith from the University of Sydney’s School of Public Health pointed out that this hasn’t deterred laboratories, influencers, and medical professionals worldwide from promoting these tests on social media. In an analysis of 188 social media posts that mentioned Alzheimer’s or dementia alongside blood tests, Smith and her team found that these posts reached an audience of over 114 million across platforms like Facebook, Instagram, and TikTok.

Interestingly, about 10% of the posts were from doctors suggesting that the tests could be beneficial for screening asymptomatic individuals, with a significant number of these posts originating from the U.S. Smith noted that some doctors appeared to have clear financial motives in promoting these tests. However, she also acknowledged that not all posts were alarmist; some medical professionals provided nuanced information in longer videos, discussing both the benefits and limitations of these blood tests.

The findings of this research were published in the Journal of the American Geriatrics Society. The study indicated that over one-third of social media posts endorsed testing for asymptomatic individuals, and accounts with financial interests were more than three times likely to promote such tests.

Smith cautioned about the potential harms, including unnecessary diagnoses without a clear next step. “Healthy individuals who take these tests may receive a positive Alzheimer’s diagnosis but could very well not progress to dementia,” she remarked. The uncertainty surrounding follow-up actions after a positive result raises concerns, especially since most treatments studied have focused on individuals already showing cognitive impairment or dementia, meaning their efficacy for healthy individuals remains unknown.

She also flagged the possible side effects and costs of treatments, as well as the psychological impact of a diagnosis—not just for individuals, but for their families and communities too. Prof. Susan Kurrle, president of the Australian and New Zealand Society for Geriatric Medicine, emphasized that tests should only be prescribed by physicians in specific circumstances. “There should be a high pre-test probability of early Alzheimer’s before proceeding with such tests,” she added, clearly stating that these are not meant for general screening.

In Australia, these tests can cost up to $400 when ordered through a doctor and aren’t covered by Medicare. Those seeking tests online face fees of up to $600, often without proper pre-test evaluations. Another provider offers the test for $365 but does not require pre-screening.

Kurrle warned that a positive result could lead to undue stress about developing dementia, while a negative result might mislead individuals into neglecting addressable risk factors, such as maintaining physical activity or managing vascular health issues like high cholesterol or sensory losses.