Are social isolation and loneliness one and the same thing?

Human beings are social creatures. Our connection to others enables us to survive and thrive. Yet, as we age, many of us are alone more often than when we were younger, leaving us vulnerable to social isolation and loneliness—and related health problems such as cognitive decline, depression, and heart disease. Fortunately, there are ways to counteract these negative effects. Social isolation and loneliness do not always go together. Some people feel lonely despite being surrounded by family and friends.

Health effects of social isolation, loneliness

Research has linked social isolation and loneliness to higher risks for a variety of physical and mental conditions: high blood pressure, heart disease, obesity, a weakened immune system, anxiety, depression, cognitive decline, Alzheimer’s disease, and even death.

People who find themselves unexpectedly alone due to the death of a spouse or partner, separation from friends or family, retirement, loss of mobility, and lack of transportation are at particular risk.

Conversely, studies show that people who engage in meaningful, productive activities with others tend to live longer, boost their mood, and have a sense of purpose. These activities seem to help maintain their well-being and may improve their cognitive function.

Breaking ground in loneliness research

Research has found that being alone and loneliness are different but related. Social isolation is the objective physical separation from other people (living alone), while loneliness is the subjective distressed feeling of being alone or separated. It’s possible to feel lonely while among other people, and you can be alone yet not feel lonely.

The misery and suffering caused by chronic loneliness are very real and warrant attention. As a social species, we are accountable to help our lonely children, parents, neighbours, and even strangers in the same way we would treat ourselves. Treating loneliness is our collective responsibility.

Although there is more to learn, the understanding of the mechanisms of action of loneliness and its treatment has increased dramatically since scientific investigation began more than two decades ago. Findings are that loneliness automatically triggers a set of related behavioural and biological processes that contribute to the association between loneliness and premature death in people of all ages. 

Understanding the biology of loneliness

Losing a sense of connection and community changes a person’s perception of the world. Someone experiencing chronic loneliness feels threatened and mistrustful of others, which activates a biological defence mechanism.

For example, loneliness may alter the tendency of cells in the immune system to promote inflammation, which is necessary to help our bodies heal from injury. But inflammation that lasts too long increases the risk of chronic diseases.

Loneliness acts as a fertiliser for other diseases. The biology of loneliness can accelerate the build-up of plaque in arteries, help cancer cells grow and spread, and promote inflammation in the brain leading to Alzheimer’s disease. Loneliness promotes several different types of wear and tear on the body.

People who feel lonely may also have weakened immune cells that have trouble fighting off viruses, which makes them more vulnerable to some infectious diseases. Having a sense of mission and purpose in life is linked to healthier immune cells. Helping others through caregiving or volunteering also helps people feel less lonely. Working for a social cause or purpose with others who share your values and are trusted partners puts you in contact with others and helps develop a greater sense of community.

Researching genetic and social determinants of loneliness

Researchers are trying to understand the differences between social isolation and loneliness and how they may influence health. They are also trying to identify potential interactions between genes and the environment of older adults affected by social isolation and loneliness.

Individuals who are not prone genetically to feeling lonely may, for example, suffer much less from social isolation, while others feel lonely even though they are surrounded and part of a rich social life.

We need to identify people who are most prone to suffer from social isolation and loneliness and those who would benefit most from interventions. Interventions for social isolation may look very different from interventions for those who feel lonely. Scientists are beginning to apply a framework to research on social isolation and loneliness.

Future research will need to clarify the extent to which loneliness and social isolation are malleable, and if so, what are the most effective approaches? Research is also needed to clarify how great a change in loneliness or social isolation is required to achieve a flexible change in health.

Extracts taken from https://www.nia.nih.gov