Occasionally, everyone grapples with feelings of loneliness. Elementary examples include transitioning to a new school or location, the departure of a child for university, or grieving the death of a partner. However, for some individuals, loneliness is not merely temporary, but a consistent experience.
This type of chronic loneliness eventually morphs into a defining characteristic of a person’s personality, informs Dr Ellen Lee, an associate psychiatry professor at the University of California, San Diego. Individuals afflicted in this manner often exhibit behaviours influenced by a persistent sense of alienation.
There is an ever-increasing body of research suggesting that such pervasive loneliness negatively impacts our health and has the potential to alter the brain. This increases the risk for developing neurodegenerative diseases. The following is an overview of what experts understand about the effect of chronic loneliness on the brain, and some potential strategies to combat it.
Humans, now characterised as inherently sociable beings, likely evolved this way due to the dangers inherent in isolation for our ancient forebears, which would have threatened survival. Scholars theorise that loneliness may have evolved as a specific stress signal, intended to promote the seeking of companionship.
However, when loneliness becomes chronic, this stress response becomes dysfunctional, mirroring the way anxiety, initially a beneficial response to fear, can degenerate into a debilitating mental disorder. Anna Finley, a postdoctoral research fellow at the Institute on Aging at the University of Wisconsin-Madison, elaborates, “Brief moments of loneliness typically stimulate people to pursue social interaction. However, chronic loneliness appears to reverse this effect”, by making subjects hyper-aware of social threats and potential rejection, thereby rendering social interaction more intimidating and less enjoyable.
Studies reveal that lonely individuals are highly sensitive to negative social expressions such as ‘disliked’ or ‘rejected’, as well as to faces portraying negative emotions. Additionally, they exhibit a diminished response to images of strangers in enjoyable social circumstances, suggesting that they may derive less pleasure from positive interactions. In the brain, constant loneliness corresponds with alterations in areas critical for social cognition, self-consciousness, and emotional processing.
Can such a subjective sentiment truly exert a dramatic influence on the brain’s architecture and operational mechanisms?
Scientists are of the opinion that the occurrence of stress from loneliness not only spurs the immune system into action but also elevates the levels of certain chemicals causing inflammation. With prolonged exposure, such stress and inflammation can adversely affect mental health by inflicting damage onto neurons and their interconnections.
For quite some time, the scientific community has been privy to the link between loneliness, Alzheimer’s disease and various other forms of dementia. A rather recent study has also hinted at a possible connection with Parkinson’s disease.
Dr Nancy Donovan, heading the division of geriatric psychiatry at Brigham and Women’s Hospital, notes even slight feelings of loneliness increase the risk of developing dementia, with the risk increasing in line with levels of loneliness. She points out that people who exhibit higher levels of loneliness have been shown to also possess elevated amounts of proteins amyloid and tau, two key indicators of Alzheimer’s disease, in their brains even in the absence of cognitive deterioration symptoms.
Scientific consensus leans toward the view that stress and inflammation, consequences of loneliness, are suspected of instigating or accelerating the progression of neurodegenerative diseases particularly in older adults. Dr Donovan brings attention to the detrimental effects that loneliness-induced stress on the cardiovascular system, leading to heightened blood pressure and heart rate, can additionally have on the brain.
Loneliness affects mental and physical health in a more generic sense which might also contribute to cognitive decline. It is tightly intertwined with depression, another factor that boosts dementia risk, and increases the likelihood of physical inactivity and tobacco use. Dr Ellen Lee states, “All these different factors could influence the ageing of our brains. I believe numerous routes exist connecting loneliness to cognitive decline.”
Past studies focusing on loneliness and neurodegeneration have primarily targeted middle-aged and older adults, leaving the risk factor for loneliness during childhood or early adulthood relatively unknown. However, Dr Wendy Qiu, a professor of psychiatry and experimental pharmacology and therapeutics, has found that midlife loneliness experienced only fleetingly and not long-term does not enhance dementia risk.
Dr Qiu highlights the brain’s proven capacity for recovering from temporary bouts of loneliness. However, sustained feelings of loneliness, without the necessary ‘rescue’ intervention, can become detrimental to the brain.
A common suggestion for alleviating chronic lonliness is straightforward – aim to form new friendships. This can be accomplished through engaging in group activities such as art gatherings, sporting teams, aid communities or committing to volunteer work. The underlying objective is to immerse oneself in environments that foster unity.
However, Dr Lee points out these contrived social situations might not be uniformly effective. He argues their success hinges on the presence of a ‘mutual identity’ within the participants, as seen in groups specifically designed for people with commonalities like being widowed or diabetic. This provides a shared identity to bond over.
The other half of the solution lies in addressing the individual’s perceptions and thought processes related to social encounters. This can be achieved through cognitive behavioral therapy. Dr Lee believes these methods can be slightly more impactful as they ‘dig deep’ into the issue, unearthing the reasons why an individual might struggle to engage socially.
While these strategies may seem rudimentary, executing them proves to be more challenging. As Finley pointed out, this remains a ‘complex issue’. The original publication of this article was in the New York Times.