The New Alzheimer's Test Is Part of a Billion Dollar Con

Care to kick a puppy, anyone?

I remember watching a 60 Minutes segment in 2011 that broke my heart. A man with ALS, the incurable, progressive condition that slowly robs a person of neurologic motor function, sobbed as he recounted the hope he felt when paying $47,000 to a con man for a new ‘high-tech’ treatment.

I thought of him while reading this month’s news reports about the new blood test for Alzheimer’s, a similarly progressive, dreaded, and often heartbreaking condition. But alas, it turns out the blood test is not for Alzheimer’s at all. Yet most journalists and doctors don’t know that. The test is actually for amyloid plaques in the brain, the same ones targeted by two fancy new Alzheimer’s drugs just approved by the FDA. What a coincidence!

Here’s how the con works.

Alzheimer’s Disease is a pathologic diagnosis, meaning it can only be confirmed with a microscope at autopsy. A final, formal diagnosis, in other words, requires seeing the neuro-fibrillary tangles and plaques that are defining markers of the disease. Therefore diagnosing Alzheimer’s in live people is fraught. Other causes of dementia (vascular, Lewy Body, fronto-temporal, etc.) are also pathologic diagnoses, and they lead to neurologic disabilities that often overlap with, and can even be identical to, those seen in Alzheimer’s. But doctors do their best, and they’re usually right.

What’s even trickier is that the microscopic findings, plaques and tangles, are present in lots of people who never exhibit or experience Alzheimer’s dementia. This is something researchers discovered with specialized brain imaging that partly visualizes the plaques. According to a recent report from the Mayo Clinic based on that imaging, by age 85 roughly 60% of people have amyloid plaques, but only 10% have dementia.

Yet the blood test, which the Times described as “much more accurate” than doctors, tests exclusively for the plaques. And not only are there many perfectly healthy people with amyloid plaques in their brain, the Mayo research found even people with plaques who had early signs of dementia mostly did not progress to Alzheimer’s during four years of follow-up. In other words even with cognitive impairment AND amyloid plaques in the brain, most people didn’t have Alzheimer’s. Meanwhile, 15% of those with early dementia and no plaques soon developed Alzheimer’s dementia.

Now what do you think of a blood test for amyloid? It misses 15% of early Alzheimer’s cases, and calls more than half of 85-year olds diseased when 90% of them are healthy. Using this test to diagnose Alzheimer’s is like using cholesterol to diagnose heart attacks. While it may be a risk factor loosely (at best) correlated with heart problems down the line, most people with high cholesterol never have a heart attack, and most people with heart attacks don’t have high cholesterol.

Why would researchers be parading a ‘test’ this bad? Because they’ve been captured by an idea—the Amyloid Hypothesis. I wrote about the theory in April after breathless news coverage of one of the new anti-amyloid drugs.

The hypothesis is elegant, and alluring: Amyloid plaques cause Alzheimer’s, and removing them can cure or improve the disease. Unfortunately anti-amyloid drugs have failed to help people with Alzheimer’s (despite removing the plaques) over and over and over. Indeed, many believe the Amyloid Hypothesis blossomed only after a highly cited 2006 study—which was retracted this June, 18 years later, after investigators found the lead author manipulated and fabricated data.

But the drug companies, who have invested billions, know there’s a yawning gap between amyloid plaques and Alzheimer’s dementia, and their best remaining chance is to turn the plaques themselves into the disease. The new test does exactly that.

It’s a brilliant strategy since it would mean 1 in every 6 people in their 60s, 1 in 3 in their 70s, and most people in their 80s, suddenly have ‘Alzheimer’s Disease’ despite being perfectly normal. And presto! We have a new, brazenly profit-driven definition of Alzheimer’s, endorsed and popularized by unsuspecting journalists who didn’t understand the study. (Kudos to the few who did).

Eminent geriatricians have pointed out this new definition is preposterous and harmful. But the failed test and failed drugs continue marching toward ubiquity at an estimated drug cost of more than $30,000 per person, per year, for life. This is despite the drugs causing brain swelling in 1 out of 4 who take them, and routinely killing participants even in carefully monitored, highly selective company trials. 

What makes all of this possible, of course, is the lack of an effective treatment for Alzheimer’s, a diagnosis that breeds desperation. The twisting of science exists, in this case, to exploit human hope. It is a confidence game like the one I saw years ago on 60 Minutes, and it is heartbreaking.

Despite an ever-increasing array of strategies for improving and extending the lives of people with Alzheimer’s, profit-driven research and mass media hype are now priming millions of people and families for a future of dashed hopes and misplaced effort, while bankrupting a nation.