It seemed like a sensible suggestion to assess the capabilities of an 81-year-old man seeking voter approval to remain in the White House until January 2029.
To reassure the American people, ABC's George Stephanopoulos asked President Biden: Would he be willing to take a cognitive test and share the results with the American people?
Biden was reluctant. In the exercise of his duties as leader of the free world, he said: “I take a cognitive test every day.”
Though the president dismissed the suggestion, medical experts said the idea of Biden — along with his 78-year-old rival, former President Trump — undergoing some form of cognitive testing had merit.
“Let’s give this to both of them,” he said. Dr. Louise Aronsongeriatrician at the University of California, San Francisco.
Kevin Duff, a neuropsychologist at the Alzheimer's Disease Research Center at Oregon Health & Science University, compared the proposal to the long-standing practice of requiring presidential candidates to release their tax returns.
There would be several types of tests to choose from. A simple screening exam might involve just a few questions and be completed in minutes. An in-depth evaluation could take an entire day.
When former White House physician Dr. Ronny Jackson evaluated Trump in 2018, he opted for the popular Montreal Cognitive Assessment, or MoCA Test. Over the course of about 15 minutes, patients are asked to recall a list of five words, draw a clock with the hands set to a particular time, perform subtraction with two-digit numbers and think of the names of animals in a drawing, among other tasks. At the time, Trump scored a perfect 30 out of 30.
Whether long or short, a good test measures multiple “domains of cognition,” Aronson said. There’s short-term and long-term memory. There’s the ability to communicate through spoken and written language. There’s attention, comprehension, judgment, reasoning, problem solving, decision making and more.
“If a person gets an excellent grade on an exam, that tells you something,” he said. Dr. Laura Mosquedaprofessor of family medicine and geriatrics at the Keck School of Medicine of USC. “And if they fail a test, that tells you something.”
A mid-range score can be trickier, experts say.
An abnormal result on a cognitive test does not necessarily mean that a patient has a true cognitive problem. In about 10% of cases, it can be attributed to a medication side effect, an infection, a thyroid problem, a vitamin deficiency, a mood disorder such as anxiety or depression, or something else that is reversible.
“What we see all the time as geriatricians is reactions to medications,” Aronson said. “I can’t tell you how often we take medications off and then the person goes back to normal.”
Sometimes it's even simpler than that.
“I’ve seen people who had been diagnosed with dementia and who actually had a hearing problem, but they didn’t want to admit it,” Mosqueda said. “They couldn’t hear the questions and so they gave strange answers.”
Some cognitive changes are a normal part of the aging process. The speed of thought is a clear example.
“As we get older, we’ll do things more slowly,” Aronson said. That’s not necessarily a sign of cognitive decline, she said, recalling a 101-year-old patient who only failed one item on a test but needed more time to complete it.
If a patient's cognitive problems persist, or if caregivers wish to better understand the details of their condition, further evaluation may be necessary.
The tasks are more challenging, Duff said. For example, instead of seeing if a patient can recall five words after five minutes, a neuropsychologist might give the patient 15 words and see how many he or she remembers half an hour later.
On the MoCA test, a score of 25 or less is considered abnormal regardless of any other factors. With a more sensitive test, results are compared to the performance of other people of the same age, educational level, occupational history and other characteristics, Duff said.
Experts agreed that a person with Biden's background would likely do well on a MoCA test even if his or her cognition had declined.
“In some patients who are particularly verbal, they won’t remember the word they want, but they’ll be able to figure out how to find it,” Aronson said. In those cases, a normal score on the test “wouldn’t necessarily rule out cognitive impairment.”
Duff said it would be like having an IndyCar driver who wants to compete in the Indianapolis 500 take the same driving test the DMV uses for 16-year-olds.
“My concern is that a relatively easy test still doesn’t mean you’re up to the challenge of leading one of the most powerful countries in the world,” he said.
This isn't a problem unique to presidential candidates. It may be appropriate to ask airline pilots, bus drivers, surgeons and others with jobs that involve a high degree of responsibility to undergo cognitive testing as they age, experts said.
“I think you can argue that this is a job where the brain should function pretty well,” Aronson said.
There is no consensus among experts on whether all older adults should be screened for cognitive decline. The U.S. Preventive Services Task Force evaluated the issue in 2020 and determined there was insufficient evidence to make a blanket recommendation one way or the other.
One reason for the hesitancy is that screening tests aren't good enough, said Dr. Colleen Christmas, a geriatrician at the Johns Hopkins School of Medicine.
“You're going to catch a lot of people who don't have problems, and you're going to miss a lot of people who do,” he said.
There is also the fact that the aging process varies greatly from person to person.
“It’s incredibly heterogeneous,” Christmas said. “There’s no way to say that 80 equals old and 75 equals young.”
Moreover, no single test, no matter how sensitive, can provide a complete picture of a patient’s cognitive function. Doctors also need the results of blood tests, brain scans and information from family members, among other things. If an MRI revealed evidence of several small strokes in parts of the brain that match the patient’s cognitive deficits, for example, it would suggest a diagnosis of vascular dementia.
“It’s like putting together a puzzle,” Mosqueda said.
Biden may be in a unique position, but his irritated reaction to the idea of taking a cognitive test was fairly typical, Christmas said.
“I think people are so afraid of being diagnosed with dementia that it’s upsetting when a doctor or family member suggests that cognitive testing is necessary,” she said. “It’s a really scary prospect.”
