Finding ways to treat apathy could be key in slowing neurodegeneration as we age, according to the study, published Wednesday by researchers from the University of California, San Francisco, on Wednesday in Neurology, the medical journal of the American Academy of Neurology.
"Apathy can be very distressing for a family member, when people no longer want to get together with family or friends or don't seem interested in what they used to enjoy," said Dr. Meredith Bock, a clinical fellow at the UCSF Weill Institute for Neurosciences, in a news release.
Bock and her team concluded that those with severe levels of apathy were 80% more likely to develop dementia than those with low levels of apathy, after adjusting for age, education and other dementia risk factors.
"While depression has been studied more extensively as a predictor of dementia, our study adds to the research showing that apathy also deserves attention as an independent predictor of the disease," Bock said. "In fact, we believe that apathy may be a very early sign of dementia, and it can be evaluated with a brief questionnaire."
A reason for earlier treatment
An estimated 5 million Americans age 65 or older had dementia in 2014, a figure that is projected to nearly triple to 14 million by the year 2060, according to
the US Centers for Disease Control and Prevention.
More research confirming apathy as a dementia risk factor could help in finding how best to target early dementia interventions in the future.
"We could be giving treatment too late in the course of the disease," Bock said.
That's because the results could indicate that apathy is a characteristic of an early stage of dementia, in what's called the prodromal stage, Bock said. In that stage, the person remains fully functional and the early effects of dementia, such as memory problems and confusion, can't be detected through interviews or testing.
Determining which attributes or traits are associated with an actual dementia diagnosis years later is key to better understanding the prodromal stage of dementia, when one's memory is deteriorating and early neurodegeneration is taking place.
Bock and her team analyzed data from 2,018 adults from a cohort of the Health, Aging, and Body Composition study, often called the Health ABC study, a prospective cohort group of community-dwelling White and Black older adults.
The group's average age was 74 and each began the study without a diagnosis of dementia.
The study looked at Medicare-eligible adults ages 70 to 79 -- with an average age of 74 -- enrolling subjects in Memphis, Tennessee, and Pittsburgh, Pennsylvania, between May 1997 and June 1998. It included a roughly equal number of Black and White subjects over the following decade. The researchers tracked those subjects' responses three times over 10 years.
Just under 19% of participants had developed dementia by the end of the study. That includes 14% in the low apathy group, 19% in the moderate apathy group and 25% in the severe apathy group.
Lessons for the pandemic
All of the data was gathered long before this year's pandemic, so participants' lack of interest in going out can't be attributed to lockdowns or fear of infection. But the results do give an insight into how the pandemic could be contributing to neurodegeneration.
"In my clinical experience with the elderly, all kinds of mood symptoms are worse during the pandemic," she said.
With elderly populations particularly at risk for death from Covid-19, and therefore reluctant to go out or engage with groups, Bock explained that the inability to go out or engage in the usual activities shouldn't be confused with a lack of interest or desire to do those things.
Even if an older adult is social distancing or quarantining, that doesn't mean their actual motivation in going out and socializing when it is safe has waned at all.
It complements other dementia studies
"There are a number of non-cognitive features that seem to be surfacing earlier in the course of dementia," said Joe Verghese, division chief in the department of geriatrics at the Albert Einstein College of Medicine. "It looks like apathy is happening fairly early in the course (of the disease)."
The study complements work Verghese and fellow researchers published
in the Journals of Gerontology in May, which focused on older adults with preexisting neurological illness such as mild cognitive impairment, stroke or Parkinson's disease.
Verghese found that apathy was associated with motoric cognitive risk syndrome, a predementia syndrome characterized by slow gait and cognitive complaints. The results suggested that designing treatment plans focused on apathy might slow down the onset of dementia.
Those treatments could include engaging in more social activities, getting more physical exercise, behavioral interventions and being prescribed medications for apathy by a specialist, Verghese said.
"The main goal of all of this is to provide better care for our aging population," Bock said.