Lonely for Life? Differences between Chronic and Transient Loneliness and their Impact on Depression in Older Adults

Loneliness is often defined as distress resulting from disparity between desired and perceived social connections (1). Feelings of loneliness have been described since ancient times and is defined in the literature as an intense desire for kinship and social relationships(2). However, during the start of the 19th century, when industrialization contributed to a reduction in social networks, prevalence rates and health consequences of loneliness began to increase(2). Over the past several decades, hastened by the COVID-19 pandemic, the prevalence of loneliness has exploded with rates as high as 49%(3). In the United States alone, over one-third of adults aged 45 years and older suffer from loneliness(4). Furthermore, the DSM-5TR has designated loneliness as a symptom (Criterion C) of Prolonged Grief Disorder (PGD) and is an important target of PGD therapy(5). Loneliness is associated with harmful physical and mental health outcomes such as cardiovascular disease, cognitive dysfunction, dementia, and all-cause mortality(6). Consequently, loneliness has been dubbed as a “behavioral epidemic” by a former U.S. surgeon general, thus raising the alarm about the impact of loneliness and social isolation in the United States(2).

In their study, Domenech-Abella and colleagues aim to distinguish between transient and chronic loneliness, recognizing the chronicity of loneliness as an essential construct that has traditionally been understudied in loneliness research. Most loneliness scales assess loneliness as a chronic persistent trait without a clear timescale. Transient loneliness refers to subacute feelings of loneliness that materialize after a stressful life event (i.e., retirement, loss of close contacts). Meanwhile, chronic persistent loneliness is closely related to maladaptive social cognition, limited social support, and insufficient intimate relationships and tends to persist for several years. Transient loneliness may serve as a “warning bell” for individuals to seek companionship and social support, whereas chronic loneliness may lead to social withdrawal, worsening loneliness and associated health outcomes.

The authors examined different social network factors such as gender, marital status, age, income, educational level, living status, quality and quantity of social relationships, functional status, and societal values, such as cultural individualism or collectivism, as well as their relationship with transient versus chronic loneliness among over 45,000 participants from the Survey of Health, Ageing, and Retirement in Europe (SHARE) study. The SHARE study was a multidisciplinary longitudinal study on aging that provided comparative data in Europe and Israel and included older adults aged> 50 years. The analyses were conducted using two distinct measures of loneliness: 1) the three-item UCLA Loneliness Scale and 2) a direct single-item question “How much of the time do you feel lonely?” Furthermore, they analyzed the relationship between chronic and transient loneliness and depression. They hypothesized that 1) chronic and transient loneliness would have different causes, consequences, and risk factors; and 2) chronic loneliness would be more strongly associated with depression than transient loneliness. This study found that 10% of the 50+ year old sample reported feeling lonely (by the UCLA loneliness scale), with 47% of the lonely sample with chronic loneliness. In support of their hypotheses, the authors found that being single, female, with a low educational level, poor physical health, lacking social network, and living in an individualistic society were risk factors for both chronic and transient loneliness, but were more robust for chronic loneliness. Additionally, chronic loneliness (assessed as having loneliness at baseline and at the 2-year follow-up timepoint) had stronger cross-sectional and longitudinal associations with depressive symptoms than transient loneliness.

The distinct nature of transient and chronic loneliness is critical to understanding the personalized and heterogeneous nature of loneliness. Loneliness interventions for older adults lack universal effectiveness(7), as a “one size fits all” approach does not seem to address the specific nature of loneliness for each individual. Recent studies have examined momentary loneliness, using ecological momentary assessment (EMA) to assess how social contexts influence immediate feelings of loneliness as sampled several times within a single day (8). These findings have highlighted how among individuals of different genders and race/ethnic backgrounds, micro- and macro-level social contexts (home, neighborhood, etc.) have varying influences on momentary loneliness. By assessing loneliness at multiple timescales, the field gains a deeper understanding of the risk and protective factors underlying social functioning, as well as the insight to develop targeted and personalized loneliness interventions.

Loneliness and depression are strongly interrelated, with loneliness contributing to the development of depressive symptomatology, particularly among older adults (9).

Loneliness appears to be a risk factor for late-life depression, with higher levels of loneliness leading to worsening of depressive symptoms and decreased remission (10). Loneliness and depression can act synergistically to reduce psychological well-being among older adults (10). However, whether depression can worsen feelings of loneliness is yet to be determined. A longitudinal study completed by Cacioppo et al. exhibited that loneliness predicted increased depressive symptoms, but depressive symptoms did not impact future loneliness(9). Other studies showed reciprocal longitudinal relationships between loneliness and depression (10, 11). Importantly, loneliness increases risk for developing depression – which contributes to the negative cognitive, mental, and physical outcomes associated with loneliness.

Social networks can influence the relationship between loneliness and depression(12). Perceived emotional support, instrumental support, and large, diverse social networks are protective against depression(13). Conversely, social network factors such as female gender, being single, older age, low income, living alone, poorer quality of social relationships, and lower educational levels are significantly related to loneliness (14). A study by Liu et al. showed that social support mediates the effect of loneliness on depression and can potentially be a protective factor against the development of depression in older adults with loneliness (15). In a prior study, Domenech-Abella et al. examined the role of social networks in the relationship between depression and loneliness in Spanish seniors, and they found that smaller social networks with less frequent social interactions play a role in the relationship between loneliness and depression (12). They concluded that increasing social interactions may be beneficial in older adults with loneliness to reduce the prevalence of depression (12).

Thus, identification of risk factors for chronic loneliness while implementing strategies that can allow for increased social networks in older adults can potentially lead to a favorable trajectory and decrease the risk of depression. Several interventions at the individual level have been proposed, including those that allow for enhanced opportunities for social interactions, improving social skills, enhancing social support, and correcting maladaptive social cognition(2). Senior programs where older adults have an increased chance for daily interactions and contact with others can be useful. Additionally, levels of compassion, self-compassion, and other components of wisdom were found to be inversely associated with loneliness after controlling for different variables (2). These traits can be enhanced through behavioral interventions, potentially as a way to improve loneliness for specific individuals (2). However, more research is needed to examine the role of prosocial behaviors and wisdom in older adults with depression and other mental illnesses. Furthermore, focused research is needed to better understand the biological underpinnings of loneliness and social functioning which may allow for the targeted development of pharmacological and mind-body interventions(2).