Daily loneliness linked to increased physical symptoms in middle age, study finds

By Dr. Liji Thomas, MDReviewed by Benedette Cuffari, M.Sc.Jun 17 2024

A recent study published in the journal Health Psychology examines the impact of daily loneliness on physical health in middle age.

Study: Loneliness dynamics and physical health symptomology among midlife adults in daily life. Image Credit: fizkes / Shutterstock.com

Midlife loneliness

Midlife is often accompanied by several significant changes in one's life, such as children becoming adults and making independent decisions, adults becoming caregivers for older adults, and deteriorating health. These changes can lead to different social interactions, positions, and roles, which may increase feelings of loneliness at various times.

Loneliness is a significant health concern, particularly among affected adults during midlife and old age. Loneliness has been associated with an increased risk of depression, cardiovascular disease, and mortality.

Most research on loneliness has studied this symptom at a single point in time. Comparatively, the current study's researchers considered loneliness dynamically to better understand how this trait functions at different time points.

About the study

The current study utilized daily diary records from 1,538 middle-aged adults, 61% of whom were women. All study participants were also interviewed over the telephone to assess their perception of daily loneliness, physical symptoms, and other daily experiences.

The average daily loneliness, the difference in loneliness on successive days, and the degree of stable loneliness were also assessed. These factors were compared with the number and severity of symptoms experienced by each study participant.

Average daily loneliness was assessed from the perception of loneliness across multiple days, thus accounting for short-term changes. This approach is more predictive of mental illness than trait loneliness and, as a result, was selected as a measure potentially associated with physical symptoms.

Loneliness variability involves both within the individual experience and between individuals. Within-person (WP) loneliness is often assessed as the deviation from the individual average loneliness and can be associated with stress, a higher risk of chronic disease, lower mental well-being, and greater inflammation.

Loneliness variability also includes stability, which reflects how much loneliness changes across successive periods. This could indicate short-term instability over time, which is associated with poorer mental health and less movement towards social goals. Little is known about how these aspects of loneliness variability affect physical health.

Another important aim of the study was to explore the interactions of these different measures and how they affect health outcomes.

What did the study show?

Study participants reported fewer and milder physical symptoms on days when they were less lonely. Those with loneliness scores above the sample average had 3.6 times the physical symptoms for every standard deviation (SD) increase.

When loneliness scores exceeded mean loneliness, physical symptoms increased by 1.32 for every SD. Those who reported higher fluctuations in loneliness over a period of eight days were more symptomatic. With increased average loneliness and above-average instability, symptom severity also increased.

For people with a higher mean level of loneliness, greater stability and instability were associated with 2.7 and two times more physical symptoms, respectively. With more significant variability in loneliness, symptom severity increased the greatest among those who were less lonely.

Conclusions

In the current study, loneliness was strongly associated with daily physical symptoms like headaches and nausea in a healthy sample of middle-aged Americans, thus corroborating previous research. The study findings emphasize the need to examine the complex dynamics of loneliness and how they vary based on the outcome being measured.

Each aspect of loneliness, including mean loneliness, loneliest days, or greatly fluctuating loneliness, showed distinctive interactions with the number and severity of physical symptoms. The highest association was observed among people with the greatest variability in daily loneliness.

Public health interventions addressing loneliness may be most effective if they support social connectedness in people’s everyday lives in ways that promote stable, low levels of loneliness.”

Appropriate programs should encourage the building of social connections and physical health to ensure greater health and well-being. These interventions are already offered to younger adults and should be extended to adults in midlife.

In the current study, daily loneliness was low compared to clinical samples, which may account for the weaker associations. The higher stability of loneliness at low levels could indicate the presence of solid and rewarding social connections, thus suggesting an area for future work.

The mechanisms of association between loneliness and physical symptoms remain unclear. Thus, future research is needed to better understand the impact of depression or neuroticism on physical symptoms and their effect on loneliness stability.