A lengthy report by the Department of Justice on President Biden’s handling of classified documents contained some astonishing assessments of his well-being and mental health.
Mr. Biden, 81, was an “elderly man with a poor memory” and “diminished faculties” who “did not remember when he was vice president,” the special counsel Robert K. Hur said.
In conversations recorded in 2017, Mr. Biden was “often painfully slow” and “struggling to remember events and straining at times to read and relay his own notebook entries.” So impaired was Mr. Biden that a jury was unlikely to convict him, Mr. Hur said.
Republicans were quick to pounce, some calling the president unfit for office and demanding his removal.
But while the report disparaged Mr. Biden’s mental health, medical experts on Friday noted that its judgments were not based on science and that its methods bore no resemblance to those that doctors use to assess possible cognitive impairment.
In its simplest form, the issue is one that doctors and family members have been dealing with for decades: How do you know when an episode of confusion or a memory lapse is part of a serious decline?
The answer: “You don’t,” said David Loewenstein, director of the center for cognitive neuroscience and aging at the University of Miami Miller School of Medicine.
The diagnosis requires a battery of sophisticated and objective tests that probe several areas: different types of memory, language, executive function, problem solving, and spatial skills and attention.
The tests, he said, determine if there is a medical condition, and if so, its nature and extent. Verbal stumbles are not proof, Dr. Loewenstein and other experts said.
“Forgetting an event doesn’t necessarily mean there is a problem,” said Dr. John Morris, a neurology professor at Washington University in St. Louis.
Mr. Hur, the special counsel, based his conclusions on a five-hour interview conducted over two days — the two days following Hamas’s surprise assault on Israel — and a review of interviews with a ghostwriter recorded in 2017.
But to scientifically identify a memory problem requires that doctors assess the change in a person’s cognitive function over time and ascertain that its magnitude is sufficient to reduce the patient’s ability to perform usual activities, Dr. Morris said.
The best way to determine if such a change has occurred is to compare results from a memory test today to the results from a test taken five or 10 years ago, he added. Failing that, doctors may interview someone who knows the patient well — usually a close family member — to get a sense for whether there’s been a decline.
Recall is just one aspect of cognition, noted Dr. Mary Ganguli, a professor of psychiatry, neurology and epidemiology at the University of Pittsburgh.
To make an accurate diagnosis, a geriatric psychiatrist might ask how long the patient has been having problems with the ability to plan and organize, or to express himself or herself. If the person is forgetful, what is the person forgetting, and when?
“We want to know what particular losses were observed, not just ‘memory,’” Dr. Ganguli said. “Was it a one-off when the person was tired or sick, or is it occurring consistently and increasing in frequency?”
It’s important to rule out other possible causes that may affect cognitive function, like a stroke or a head injury, or even use of certain common drugs, Dr. Ganguli added.
For example, a frequent culprit in memory lapses is diphenhydramine (sold as Benadryl and other brands). People who take it chronically to fall asleep often become forgetful as a result. (Patients often tell her they take Tylenol at night, she said, but Tylenol PM actually contains diphenhydramine.)
Dementia has a distinctive pattern of memory loss, not to be confused with routine forgetfulness, Dr. Ganguli added. A person with dementia will typically forget recent events, like what he or she had for breakfast, but recall things from the distant past, like a wedding day.
A detailed exam might take an hour, Dr. Ganguli said, and might additionally involve interviews with family members. A family doctor might do a more abbreviated assessment, including quick memory tests like the Mini Mental State Examination or the Montreal Cognitive Assessment, known as MoCA.
In those tests, patients are asked the date and time and asked the location of the doctor’s office. They may be asked to draw a clock showing a specific time. They are told several words and, a short time later, asked to repeat them.
To assess cognitive status, Dr. Loewenstein often administers a much longer, more probative series of objective tests. It’s a basic tenet of the field never to diagnose a patient you have not seen in a medical setting, he said.
Dr. Loewenstein said he was outraged by pundits “who would have the audacity to make diagnoses by saying, ‘Oh, this person went to the refrigerator and forgot why,’ or ‘Oh, they substituted somebody’s name for another name when they have other things on their mind.’”