Shocking study finds many Alzheimer's patients might not actually have the disease

Alzheimer's patients.
(Image credit: iStock.)

A major study of thousands of Alzheimer's patients has discovered that many people diagnosed with the disease might not actually have it, The Washington Post reports. Researchers at the Memory and Aging Center at the University of California, San Francisco found that of 4,000 patients tested for the disease's telltale amyloid plaques in the brain, just 54.3 percent of mild cognitive impairment (MCI) patients and 70.5 percent of dementia patients actually had the hallmark.

While the presence of amyloid plaques does not necessarily mean someone has Alzheimer's, being negative for the plaques does confirm a person does not have the disease.

It is famously difficult to diagnose Alzheimer's, with doctors often having to make the call based on a person's symptoms alone. A true diagnosis is impossible without autopsy, although advances with spinal taps and PET scans can help detect amyloid plaques for a more certain determination. That being said, "spinal taps are invasive, and PET scans cost $3,000 to $4,000 and are typically not covered by insurance," the Post writes.

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"If someone had a putative diagnosis of Alzheimer's Disease, they might be on an Alzheimer's drug like Aricept or Namenda," explained the Alzheimer Association's director of global science initiatives, James Hendrix, who helped work on the findings. "What if they had a PET scan and it showed that they didn't have amyloid in their brain? Their physician would take them off that drug and look for something else."

The researchers' study, which began in 2016, will last four years and eventually test more than 18,000 patients. Read more about the study here.

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Jeva Lange

Jeva Lange was the executive editor at She formerly served as The Week's deputy editor and culture critic. She is also a contributor to Screen Slate, and her writing has appeared in The New York Daily News, The Awl, Vice, and Gothamist, among other publications. Jeva lives in New York City. Follow her on Twitter.