Could Loneliness Be a Symptom of Preclinical Dementia?

Caregiver, patient expert
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Loneliness as a dementia risk, particularly Alzheimer’s disease (AD), has long been considered solid science. It’s hard to quantify loneliness, as it’s not as simple as whether a person has opportunities to interact with others. Yet, the difficulty of defining loneliness has not kept researchers from studying its impact on health. For example, the National Institutes of Health (NIH) reports study results showing that "After adjustment for other risk factors, older persons with feelings of loneliness were more likely to develop dementia” than people without such feelings.

For this reason, a study that concluded that dementia is the cause rather than the effect of loneliness has made many researchers and doctors take particular notice. Lead researcher of this startling study, Nancy Donovan, M.D., is director of the Center for Alzheimer Research and Treatment at Brigham and Women’s Hospital in Boston. She and her team have determined that, in many cases, the preclinical signs of dementia may come before the feelings of loneliness.

The researchers found that the cortical amyloid burden — long associated with AD — was evident in the brains of the lonely older adults in their study before any other symptoms of cognitive issues were apparent, therefore the people weren't aware that they had AD.

Loneliness in our aging population is often addressed by encouraging older people to be more socially engaged, seek closer friendships and, in many cases, go so far as to move into communal living situations. If this study proves to be widely accepted, it could have a significant effect on the emotions of people who show signs of loneliness. How can they hope to prevent dementia by adopting more social behaviors if dementia pathology is already evident in their brains?

Brain pathology may not tell the full story

I’m not a scientist, nor am I a medical person in any capacity. Still, while I have no doubt of the validity of the findings of this study, I don’t think that these results rule out the findings of countless other studies indicating that encouraging social interaction, or at least helping elders feel less lonely, can still be a deterrent to developing the symptoms of AD. In other words, one may have the pathology of AD without any symptoms, so why give in to something that may not ever be a problem?

Scientists continue to debate why a significant number of autopsied brains from older people have the pathology — commonly known as plaques and tangles — of AD when the person never exhibited any symptoms of AD while they were alive. The current theory for explaining this occurrence seems to be what is called cognitive reserve. Cognitive reserve simply means that these people have additional brain circuits that become active when other parts of the brain become damaged by the plaques and tangles characteristic of the disease and can no longer function properly.

An individual's cognitive reserve could explain why educational levels are considered when listing the risks for developing AD. People who have higher levels of education and/or keep their brains active and challenged as they age often show fewer symptoms of AD.

Additionally, there are an increasing number of scientists who question the long-held theory that plaques and tangles are the sole cause of Alzheimer’s. An editorial in the Journal of Alzheimer’s Disease titled “A New Perspective on the Possible Cause of Alzheimer's Disease: Microbes” insists that microbes need to be studied more thoroughly as a root cause of the disease.

Other researchers are looking at gut bacteria as the cause of AD. There's a long journey yet to be taken before all cases of Alzheimer's can be explained.

How do people at risk maintain hope?

While scientists wrangle over the cause and potential treatment of AD and other types of dementia, individuals continue to live with varying degrees of risk when it comes to developing the disease. What can we do now to hang on to the hope of putting off, if not completely evading, symptoms of the disease?

They can all improve their lifestyles. Each step taken toward better care of yourself and your loved ones can help stave off the symptoms of dementia for many. Not all, but many. Even those who carry the genes for familial early-onset Alzheimer disease (eFAD), which guarantees that a person has a 50-50 chance of developing the disease, may find that socialization, diet, exercise, and other lifestyle changes could at least put off their symptoms for a time.

Back to loneliness

Loneliness has long been considered epidemic in the aging community, and that makes sense. Even older people who have family members and close friends nearby often lose their best friend — their lifelong spouse — to death or disease.

Additionally, if the ability to drive is curtailed, and chronic pain becomes a daily companion, seeking out the company of others is often too difficult to bother with. Therefore, some feelings of loss and loneliness as a part of aging are likely to be common, and these feelings of loneliness seem understandable without considering Alzheimer's as a cause.

Perhaps providing older people with relief from unwanted isolation could help ward off symptoms of dementia. Or maybe this attention could simply make the person feel better. Either way, helping others is good all around. I’d say that while studies churn around us, nothing stops us from continuing to be caring human beings.

See More Helpful Articles:

A New Perspective on the Possible Cause of Alzheimer's Disease: Microbes

Reduction of Abeta amyloid pathology in APPPS1 transgenic mice in the absence of gut microbiota (gut bacteria abstract)

The Problem of Loneliness with Aging Can be Managed