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.
Previous studies have estimated the heritability of loneliness between 37 percent and 55 percent using twins and family-based approaches. “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,” according to Nancy Pedersen, Ph.D., a professor of genetic epidemiology at the Karolinska Institutet in Stockholm, Sweden. “We are also interested in understanding what role socioeconomic status plays in such associations.”
Using data from twin studies, Dr. Pedersen and researchers found that both social isolation and loneliness are independent risk factors, and that genetic risk for loneliness significantly predicted the presentation of cardiovascular, psychiatric (major depressive disorder), and metabolic traits. Family history does not strongly influence this effect.
“We need to identify people who are most prone to suffer from social isolation and loneliness and those who would benefit most from interventions,” said Dr. Pedersen. “Interventions for social isolation may look very different from interventions for those who feel lonely.”
Beyond genetics, understanding social determinants of health, and the role of social and interpersonal processes in healthy aging and longevity, is another research direction at NIH. Scientists are beginning to apply this 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? Demonstrating that we can move the needle on these risk factors is a critical first step toward developing effective interventions,” said Dr. Nielsen. Research is also needed to clarify how great a change in loneliness or social isolation is required to achieve a meaningful change in health, she added.
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