Loneliness Gets Under the Skin: A Scoping Review Exploring the Link Between Loneliness and Biological Measures of Inflammation

BACKGROUND

Research suggests that systemic inflammation may link loneliness to adverse health outcomes, yet there is a gap in comprehensively reviewing recent evidence on the relationship between loneliness and biological measures of inflammation in adults. This scoping review synthesizes current research to address the question: Is there a definitive link between loneliness and biological markers of inflammation in adults?

METHODS

Following the methods outlined by Arksey and O'Malley, we developed a protocol, defined our research question, and systematically searched PubMed, CINAHL, Embase, and Scopus for English-language studies conducted from 2018 to 2023 exploring the relationship between loneliness and biomarkers of inflammation in adults.

RESULTS

Twelve studies meeting the inclusion criteria displayed heterogeneity in terms of sample characteristics, loneliness scales, and inflammatory biomarkers. The UCLA Loneliness Scale, in various forms, emerged as the predominant tool for measuring loneliness, while C-reactive protein and interleukin-6 were the most frequently evaluated inflammatory biomarkers. Notably, all 12 studies reported an association between loneliness and at least 1 biological marker of inflammation.

CONCLUSION

Research consistently associates loneliness with poor health outcomes in aging adults, but the underlying mechanisms remain unclear. This scoping review suggests that inflammation may serve as a pathway linking loneliness to adverse health outcomes. However, the variability across studies highlights the need for standardized measurement methods and a consideration of both the duration and extent of loneliness. Enhancing our understanding of how loneliness affects systemic inflammation may help clarify why loneliness is associated with negative health outcomes.

Loneliness and pet ownership among dependent older adults in a Southern European urban context

OBJECTIVE

Identify the role that pet ownership may play in mitigating feelings of loneliness among dependent older adults, with a particular focus on gender and mobility problems.

METHOD

We use a representative sample of dependent individuals aged 65 and over (n = 1,600), with 1,005 self-respondents in Barcelona, drawn from the 2023 Survey of Older People with Functional Dependency. Logistic regression models assess the associations between pet ownership (dog, cat, or other animal) and perceived loneliness in older dependents. Models are stratified by gender.

RESULTS

The analysis highlights that dog ownership and receiving family care are factors associated to lower risk of perceived loneliness, particularly among women. In contrast, the association between pet ownership and loneliness is less clear for men for whom no differences were observed between dog owners, other pet owners and individuals without pets in the outcome measure. Our analyses also reveal that the benefits of dog ownership hold only for old age dependents with mobility impairments.

CONCLUSION

Our results provide evidence that gender, type of pet and mobility are key variables associated to loneliness. These findings underscore the importance of considering dog ownership and family involvement in care strategies to mitigate loneliness among older dependents.

Do middle-aged and older people underreport loneliness? experimental evidence from the Netherlands

Despite the growing acknowledgment of the importance of loneliness among older individuals, questionnaire length constraints may hinder the inclusion of common multi-item loneliness scales in surveys. Direct, single-item loneliness measures are a practical alternative, but scholars have expressed concerns that such measures may lead to underreporting. Our aim was to test whether such reservations are justified. We conducted a preregistered list experiment among 2,553 people aged 50 + who participated in the Dutch Longitudinal Internet studies for the Social Sciences (LISS) panel. The list experiment method has been developed to unobtrusively gather sensitive information. We compared the list experiment estimate of the prevalence of frequent loneliness with the corresponding direct question estimate to assess downward bias in the latter. Next to pooled models, we estimated models stratified by gender to assess whether loneliness underreporting differed between women and men. Relying on the direct question, we estimated that 5.9% of respondents frequently felt lonely. Our list experiment indicated that the prevalence of frequent loneliness was 13.1%. Although substantial in magnitude, the difference between both estimates was only marginally significant (Δb: 0.072, 95% CI: - 0.003;0.148, p = .06). No evidence of gender differences was found. Although we cannot be conclusive that loneliness estimates are biased downward when a direct question is used, our results call for caution with direct, single-item measures of loneliness if researchers want to avoid underreporting. Replications are needed to gain more precise insights into the extent to which direct, single-item loneliness measures are prone to downward reporting bias.

Need satisfaction in daily well-being: Both social and solitude contexts contribute to well-being

Daily need satisfaction for relatedness (social connection), autonomy (volitional self-congruent action), and competence (self-efficacy) fosters well-being, but those findings primarily reflect experiences during social interactions. A three-week daily diary study (N = 178) explored psychological need satisfaction in two key everyday contexts: solitude and social. Holding constant the benefits of need-satisfying social contexts, autonomy satisfaction during solitude was key to peaceful affect, whereas competence satisfaction during solitude contributed to lower loneliness; both psychological needs in solitude contributed to evaluating the day as more satisfying. Relatedness-deficiency in solitude did not contribute to loneliness; instead, those who were relatedness-deficient in social interactions felt lonely. Further, need satisfaction in solitude compensated for deficient needs in social contexts, reducing loneliness (autonomy and relatedness) and increasing day satisfaction (all needs) when social contexts failed to satisfy needs. Findings suggest daily solitude can shape daily well-being and further attention is needed to understand and ultimately improve everyday solitude.

The societal cost of 'unwanted' loneliness in Spain

Unwanted loneliness negatively affects people's health and quality of life, increasing morbidity and the risk of premature death; this situation can generate major social costs. The aim of this study is to estimate the social costs of loneliness in Spain for 2021: both tangible costs -monetary value of health costs and production losses- and intangible costs -Quality Adjusted Life Years (QALYs). To estimate costs not derived from mortality, information from a sample of 400 people with unwanted loneliness was compared with that derived from two samples of the general population obtained from the Spanish National Health Surveys. To estimate the costs associated with premature deaths, the population attributable fraction was calculated using the relative risks estimated in previous survival studies. In the baseline scenario, the tangible costs of unwanted loneliness are estimated to be around 14,129 million euros in 2021, representing 1.2% of Spain's GDP. Approximately 56.8% of the tangible costs correspond to production losses due to reduced working time, and 43.2% are due to healthcare costs related with increased consultation frequency in healthcare services and higher consumption of medicines related to loneliness. In addition, loneliness generates a reduction in quality of life equivalent to 1.04 million QALYs, which corresponds to 2.8% of the total stock of QALYs of the Spanish population over 15 years of age.

Loneliness in older adults with diabetes mellitus: a scoping review

This scoping review aimed to explore and synthesize existing research on predictors of loneliness, and the impact of loneliness on physiological and psychological health outcomes and health behaviors in older adults with diabetes. Results from 12 studies showed that low education, being unmarried/divorced/separated, having diabetes-related complications, being physically inactive, having diabetes distress, being of a certain race/ethnicity, being female, having depressive symptoms, and being younger age were consistently identified as predictors of loneliness. In addition, loneliness was found to affect both psychological (depressive symptoms and negative perceptions of diabetes) and physiological health outcomes (increased postprandial blood glucose and A1C levels, decreased cortisol levels, increased MCP-1 levels, slower gait speed, and weaker hand grip) and health behaviors (decreased engagement in physical activity, increased disability in activities of daily living and instrumental activities of daily living, and increased likelihood of antidepressant use). The results of this scoping review suggest that loneliness is a complex issue for older adults with diabetes and its effects are far-reaching. Therefore, further research should be conducted to explore the potential causal relationships between loneliness and physiological and psychological health outcomes and to identify the best interventions to reduce loneliness in older adults with diabetes. For healthcare providers, it is important to recognize that loneliness is an appropriate risk factor for older adults with diabetes that may affect psychological and physiological health outcomes and health behaviors and to address it through interventions such as social support programs, group therapy, or psychosocial counseling.

Sex-differences in the association of social health and marital status with blood-based immune and neurodegeneration markers in a cohort of community-dwelling older adults

BACKGROUND

The immune system has been proposed to play a role in the link between social health and all-cause dementia risk. We explored cross-sectional and longitudinal associations between social health, immune system balance and plasma neurodegeneration markers in community-dwelling older adults, and explored whether the balance between innate and adaptive immunity mediates associations between social health and both cognition and total brain volume.

METHODS

Social health markers (social support, marital status, loneliness) were measured in the Rotterdam Study between 2002-2008. Immune system cell counts and balance were assessed repeatedly from 2002 to 2016 using white blood-cell-based indices and individual counts (granulocyte-to-lymphocyte ratio (GLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII)). Plasma neurodegeneration biomarkers (amyloid-β40, amyloid-β42, total tau and neurofilament light chain) were measured once from blood samples collected between 2002-2008. Global cognitive function and total brain volume (MRI) were measured at the follow-up visit between 2009-2014. We used linear mixed models to study longitudinal associations and performed causal mediation analyses.

RESULTS

In 8374 adults (mean age 65.7, 57 % female), never married participants (n = 394) had higher GLR, PLR and SII compared to married peers at baseline and during follow-up, indicating imbalance towards innate immunity. Being never married was associated with higher plasma amyloid-β40, and being widowed or divorced with higher plasma total tau levels at baseline. Widowed or divorced males, but not females, had higher GLR, PLR and SII at baseline. Higher social support was associated with lower PLR in females, but higher PLR in males. Loneliness was not associated with any of the immune system balance ratios. Never married males had higher levels of all plasma neurodegeneration markers at baseline. Immune system balance did not mediate associations between social health and cognition or total brain volume, but does interact with marital status.

CONCLUSION

This study indicates that marital status is associated with blood-based immune system markers toward innate immunity and higher levels of plasma neurodegeneration markers. This is particularly evident for never married or previously married male older adults compared to married or female peers.

Longitudinal associations of loneliness and social isolation with care dependence among older adults in Latin America and China: A 10/66 dementia research group population-based cohort study

OBJECTIVES

With increasing life expectancy and rapid ageing, there is an expanding number of older people who have functional declines, greater needs for care and support and who are at increased risk of insufficient social interaction. Longitudinal investigations on the interplay between loneliness, social isolation and care dependence remain limited. This study thus aimed to investigate the longitudinal reciprocal association between social isolation/loneliness and care dependence among older adults in Latin America and China.

METHODS

We analysed data from the population-based cohorts from the 10/66 Dementia Research Group (DRG) project (baseline 2003-07 and follow-up 2007-2010). The 10/66 DRG study recruited and followed up older adults aged 65 years or above in 11 catchment areas in Latin America and China. A total of 15,027 older adults from Latin America and China (mean age = 73.5, standard deviation = 6.5) were included in our analyses. Cross-lagged panel models were used to investigate potential reciprocal associations.

RESULTS

Loneliness was positively associated with care dependence at baseline (β = 0.11, p < 0.001 in Latin America; β = 0.16, p < 0.05 in China]. Social isolation consistently had a stronger positive association with care dependence across all study sites in both waves. Longitudinally, care dependence positively predicted loneliness (β = 0.10, p < 0.001) and social isolation (β = 0.05, p < 0.001) in Latin American study sites but not in China. Yet there was no statistical evidence of lagged effects of loneliness and social isolation on care dependence in all study countries.

CONCLUSIONS

Older people with care dependence are at risk of developing loneliness and social isolation. It is crucial to develop complex care models using a societal approach to address social and care needs holistically, especially for the older group with declining functional capacity. Future longitudinal research is required to explore the causal mechanisms of relationships and cultural differences, in order to inform the development of culturally appropriate care models.

Chronic loneliness and the risk of incident stroke in middle and late adulthood: a longitudinal cohort study of U.S. older adults

Background

Loneliness has been implicated as a stroke risk factor, yet studies have examined loneliness at only one time point. The association of loneliness changes and risk of incident stroke remains understudied. Our aim was to examine the association of loneliness with incident stroke, particularly the role of loneliness chronicity.

Methods

This prospective cohort study examined data from the Health and Retirement Study during 2006-2018. For analyses examining baseline loneliness only, we included U.S. adults aged 50 years or older and stroke-free at baseline and excluded individuals missing data on loneliness and those who experienced death at baseline. For analyses examining loneliness changes over two time points, we included those aged 50 years or older at baseline and stroke-free through the exposure measurement period. Individuals missing a loneliness scale measure or those who experienced death during the exposure measurement period were excluded. Loneliness was measured with the 3-item Revised UCLA Loneliness Scale. We constructed loneliness scores (range 3-9), dichotomized loneliness measures (high vs low using a >6 cutoff), and loneliness patterns across two time points (consistently low, remitting, recent onset, consistently high). Cox regression models estimated associations of baseline loneliness (N = 12,161) with incident stroke over a 10-12-year period, and loneliness change patterns (N = 8936) with incident stroke over a subsequent 6-8-year period, adjusting for demographics, health behaviors and health conditions.

Findings

Higher loneliness scores at baseline were associated with incident stroke for continuous (hazard ratio [HR]: 1.05, 95% confidence interval [CI]: 1.01-1.08) and dichotomized (HR: 1.25, 95% CI: 1.06-1.47) loneliness measures, and persisted after adjustment for social isolation but not depressive symptoms. Only individuals with a consistently high loneliness pattern over time (vs consistently low) had significantly higher incident stroke risk (HR: 1.56, 95% CI: 1.11-2.18) after adjusting for depressive symptoms and social isolation.

Interpretation

Chronic loneliness was associated with higher stroke risk independent of depressive symptoms or social isolation. Addressing loneliness may have an important role in stroke prevention, and repeated assessments of loneliness over time may help identify those particularly at risk.

Funding

National Institute on Aging (NIA U01AG009740).

Loneliness and global cognitive functioning in racially and ethnically diverse US midlife and older adults

Introduction

Few studies have examined the association of loneliness and cognitive functioning in the US. We used two common measures of loneliness and examined their association in a large sample of US Black, Latino, and White adults (ages ≥ 50).

Methods

We analyzed Wave 3 of the National Social Life, Health, and Aging Project (N = 2,757). We examined loneliness using one item from the CES-D and the Felt Loneliness Measure (NFLM); cognitive functioning was assessed using the Montreal Cognitive Assessment (MoCA) tool, where higher scores indicated better functioning. We used weighted ordinary least squares regressions to examine the effects of loneliness (CES-D loneliness and NFLM in separate models) on MoCA scores. In exploratory analyses, we examined if these relationships varied by race and ethnicity. We adjusted all models for sociodemographic and other salient factors (e.g., chronic disease, depressive symptoms, living alone).

Results

Mean age was 63.49 years, 52% were female, and 9% were Black and 6% Latino persons. Approximately 54% endorsed feeling lonely on at least one measure; 31% (CES-D) and 46% (NFLM). The relationship between loneliness measures was positive and significant, X 2 (1, N = 2,757) = 435.493 p < 0.001. However, only 40% of lonely individuals were identified as lonely on both assessments. CES-D loneliness was inversely (βˆ = -0.274, p = 0.032) associated with MoCA scores and this association did not vary by race and ethnicity. Greater NFLM loneliness was positively associated (βˆ = 0.445, p < 0.001) with higher MoCA scores for Latino participants only.

Discussion

Loneliness appears to be an important predictor of cognitive functioning. However, the association of loneliness and cognitive functioning varied when using the CES-D loneliness item or the NFLM. Future work is needed to understand how loneliness and its clinically relevant dimensions (social, emotional, existential, chronicity) relate to global and individual cognitive domains. Research is needed with racially and ethnically diverse midlife and older adults, particularly to understand our counterintuitive finding for Latino participants. Finally, findings also support the need for research on interventions to prevent cognitive decline targeting loneliness.

Efficacy of an Internet-based self-help intervention with human guidance or automated messages to alleviate loneliness: a three-armed randomized controlled trial

Loneliness is a prevalent and stigmatized phenomenon associated with adverse (mental) health outcomes. However, evidence-based interventions to alleviate loneliness are scarce. This randomized controlled trial (ClinicalTrials.gov-ID: NCT04655196) evaluated the efficacy of an internet-based cognitive behavioral self-help intervention (ICBT) to reduce loneliness by comparing two intervention groups with guidance or automated messages against a waitlist control group. Adults (N = 243) suffering from loneliness were recruited from the general public and then randomly assigned (2:2:1) to a 10-week ICBT with human guidance (GU) or automated messages (AM) or to a waitlist control group (WL). Loneliness, assessed with the UCLA-9, was the primary outcome. Outcomes were assessed at baseline and 10 weeks (post) and analyzed using mixed-effects models. The pooled intervention conditions resulted in lower loneliness scores at post-assessment than the WL (Cohen's d = 0.57, 95% CI [0.25; 0.89]) and reduced depressive symptoms, social anxiety, social avoidance behavior, and rejection sensitivity (d = 0.32-0.52). The GU group had lower loneliness scores at post-assessment than the AM group (d = 0.42, 95% CI [0.13; 0.70]). ICBT effectively alleviated loneliness, and guidance increased the reduction in loneliness compared to automated messages. Alleviating loneliness with ICBT further seems to reduce the overall burden of psychopathological symptoms.

Spouses of individuals living with mild cognitive impairment or dementia in the United States: A descriptive, population-based study

BACKGROUND

Little is known about the population of individuals who live with a spouse with cognitive impairment (CI) or dementia.

METHODS

Using the US Health and Retirement Study, 2000 to 2018, we estimated the population of adults ≥ 50 years old co-residing with a spouse with probable CI/dementia. We described their socio-demographic and health characteristics and quantified socio-demographic inequities.

RESULTS

Among community-dwelling adults ≥ 50 years old, 6% of women and 4% of men co-resided with a spouse with probable CI/dementia. Among those who were married/partnered, the prevalence of spousal dementia was greater for Black and Hispanic adults compared to their White counterparts, and for those with lower versus higher educational attainment. Among spouses, activities of daily living disability, depression, and past 2-year hospitalization was common.

DISCUSSION

Millions of older adults, disproportionately Black and Hispanic people and people with lower levels of educational attainment, live with a spouse with CI while also facing their own major health challenges.

Older men and loneliness: a cross-sectional study of sex differences in the English Longitudinal Study of Ageing

BACKGROUND

Research into men and masculinities suggests men may be more reluctant than women to state they are lonely, more reliant on partners/spouses and/or alcohol to tackle it, and that this may be a result of poorer social relationships. Ageing is often associated with loneliness, and research has indicated gendered results in older people, but existing evidence lacks generalisability and cultural context. This study tests hypotheses on sex differences in loneliness in older England-based men and women.

METHODS

We conducted a cross-sectional study using a sample of 6936 respondents aged 50 + from the English Longitudinal Study of Ageing (wave 8). Multiple imputation with chained equations was conducted to handle missing data. Multivariate regression was used to investigate the impact of sex on a direct question on loneliness whilst controlling for the University of California loneliness (UCLA) scale. Multivariate regression with interaction terms were used to examine sex differences in loneliness and alcohol consumption, partner status, and social relationships.

RESULTS

Older men were less likely than older women to state they are lonely even when controlling for UCLA score. Older men showed a greater association between loneliness and alcohol consumption, but only when measuring the number of units consumed in the last week, and not using a less precise measure of the past year. Older men who cohabited with a partner were less lonely than cohabiting older women, whereas previously married but not cohabiting older men were lonelier than their female counterparts. However, never married older men were less lonely than never married older women. Evidence was found to suggests older men's worse friendships mediated this association, but social isolation and number of close relationships did not. Severe isolation predicted greater loneliness in older women, but not older men.

CONCLUSIONS

Cultural ideals of masculinity and older men's poorer quality friendships may explain their reluctance to directly state loneliness, greater dependency on partners/spouses, and use of alcohol. Severely isolated older men may under-report loneliness on the UCLA scale as well as a direct question.

Depressive symptoms and loneliness among early adolescents: a psychometric network analysis approach

BACKGROUND

Previous studies demonstrate a high prevalence of depression and loneliness among adolescents. Although they often co-occur, the relationship between symptoms of depression and loneliness remains poorly understood. This study investigates: (a) the symptoms of depression that are connected to loneliness; (b) the role played by loneliness in the network of depression symptoms; and (c) whether the method used to measure loneliness (single-item direct or multi-item indirect) affects the relationship of loneliness with depressive symptoms.

METHODS

Participants were 496 Polish adolescents (50.8% girls) aged 11 to 13, who completed: (a) the 10-item Major Depressive Disorder subscale of the Revised Child Anxiety and Depression Scale; (b) the 11-item De Jong Gierveld Loneliness Scale (indirect loneliness), and (c) a single direct question evaluating loneliness: 'I'm lonely'. Networks were estimated using a Gaussian Graphical Model.

RESULTS

Loneliness shows a direct relationship with three affective symptoms of depression: sadness, worthlessness, and anhedonia, which mediate relationships with somatic symptoms. In contrast to previous studies, loneliness has the lowest level of centrality among all elements of the network. The method used to assess loneliness did not significantly affect the connections between loneliness and depressive symptoms.

CONCLUSIONS

Loneliness and depression overlap since they are formed by the same cognitive biases and deficits in emotion regulation but differ in the level of generality. In loneliness, they have an interpersonal context, while symptoms of depression can be intrapersonal. This helps us to understand why cognitive interventions, as compared to those which are social, are more effective in reducing loneliness.

The Role of Acceptance in Everyday Loneliness Among Adults with Serious Mental Illness

There is a high prevalence of loneliness among adults with serious mental illness (SMI) with most research focusing on stable contributing factors. This study sought to identify the role of dispositional loneliness and internalized stigma, as well as the momentary feelings of acceptance on experiential loneliness among adults with SMI. Data were collected using ecological momentary assessment via smart phones, and 89 adults with a SMI were included. Hierarchical linear modeling was used to identify the role of dispositional and experience factors in experiential loneliness. Findings indicated that (a) dispositional internalized stigma, (b) being at home, (c) being alone and, (d) a cross-level interaction between dispositional loneliness and feelings of acceptance best fit the data. The relationship of acceptance to experiential loneliness was strongest among the most lonely. Supporting people with SMI to develop social connections contributing to their relational value may enhance feelings of acceptance and reduce loneliness.

Association of cumulative loneliness with all-cause mortality among middle-aged and older adults in the United States, 1996 to 2019

Loneliness is a growing public health concern worldwide. We characterized the association between cumulative loneliness and subsequent all-cause mortality, using data from 9,032 participants aged 50+ in the population-based US Health and Retirement Study (HRS) from 1996 to 2019. Loneliness status (yes; no) was measured biennially from 1996 to 2004, and we categorized the experience of cumulative loneliness over the 8-y period as never, one time point, two time points, and ≥three time points. A multivariable-adjusted age-stratified Cox proportional hazards regression model was fitted to examine the association between cumulative loneliness from 1996 to 2004 and all-cause mortality from 2004 to 2019. Excess deaths due to each category of cumulative loneliness were calculated. Compared to those who never reported loneliness from 1996 to 2004, participants experiencing loneliness at one time point, two time points, and ≥three time points respectively had 1.05 (95% CI: 0.96 to 1.15), 1.06 (95% CI: 0.95 to 1.19), and 1.16 (95% CI: 1.02 to 1.33) times higher hazards of mortality from 2004 to 2019 (P trend = 0.01). These results correspond to 106 (95% CI: 68 to 144), 202 (95% CI: 146 to 259), and 288 (95% CI: 233 to 343) excess deaths per 10,000 person-years, for those experiencing loneliness at each of one, two, or ≥three time points from 1996 to 2004. Cumulative loneliness in mid-to-later life may thus be a mortality risk factor with a notable impact on excess mortality. Loneliness may be an important target for interventions to improve life expectancy in the United States.

Balance between solitude and socializing: everyday solitude time both benefits and harms well-being

Two literatures argue that time alone is harmful (i.e., isolation) and valuable (i.e., positive solitude). We explored whether people benefit from a balance between their daily solitude and social time, such that having 'right' quantities of both maximizes well-being. Participants (n = 178) completed a 21-day diary study, which quantified solitude time in hours through reconstructing daily events. This procedure minimized retrospective bias and tested natural variations across time. There was no evidence for a one-size-fits-all 'optimal balance' between solitude and social time. Linear effects suggested that people were lonelier and less satisfied on days in which they spent more hours in solitude. These detrimental relations were nullified or reduced when daily solitude was autonomous (choiceful) and did not accumulate across days; those who were generally alone more were not, on the whole, lonelier. On days in which people spent more time alone they felt less stress and greater autonomy satisfaction (volitional, authentic, and free from pressure). These benefits were cumulative; those who spent more time alone across the span of the study were less stressed and more autonomy satisfied overall. Solitude time risks lowering well-being on some metrics but may hold key advantages to other aspects of well-being. PROTOCOL REGISTRATION: The stage 1 protocol for this Registered Report was accepted in principle on June 1, 2022. The protocol, as accepted by the journal, can be found at: https://doi.org/10.17605/OSF.IO/5KXQ3 .

Six-year mortality associated with living alone and loneliness in Swedish men and women born in 1930

BACKGROUND

This study examined how living alone and loneliness associate with all-cause mortality in older men and women.

METHODS

Baseline data from the Gothenburg H70 Birth Cohort Studies, including 70-year-olds interviewed in 2000 and 75-year-olds (new recruits) interviewed in 2005 were used for analyses (N = 778, 353 men, 425 women). Six-year mortality was based on national register data.

RESULTS

At baseline, 36.6% lived alone and 31.9% reported feelings of loneliness. A total of 72 (9.3%) participants died during the 6-year follow-up period. Cumulative mortality rates per 1000 person-years were 23.9 for men and 9.6 for women. Mortality was increased more than twofold among men who lived alone compared to men living with someone (HR 2.40, 95% CI 1.34-4.30). Elevated risk remained after multivariable adjustment including loneliness and depression (HR 2.56, 95% CI 1.27-5.16). Stratification revealed that mortality risk in the group of men who lived alone and felt lonely was twice that of their peers who lived with someone and did not experience loneliness (HR 2.52, 95% CI 1.26-5.05). In women, a more than fourfold increased risk of mortality was observed in those who experienced loneliness despite living with others (HR 4.52, 95% CI 1.43-14.23).

CONCLUSIONS

Living alone was an independent risk factor for death in men but not in women. Mortality was doubled in men who lived alone and felt lonely. In contrast, mortality was particularly elevated in women who felt lonely despite living with others. In the multivariable adjusted models these associations were attenuated and were no longer significant after adjusting for mainly depression in men and physical inactivity in women. Gender needs to be taken into account when considering the health consequences of living situation and loneliness.

Loneliness and risk for cardiovascular disease in the United States and Japan: The effects of nationality, collectivism, and gender

RATIONALE

Loneliness is a global concern associated with adverse effects on cardiovascular disease (CVD) that may differ by nationality, collectivism, and gender.

OBJECTIVE

This study examined whether associations between loneliness and CVD indicators (e.g., metabolic dysregulation [MetD], inflammation, sleep dysfunction) would vary by nationality, collectivism, and gender. We predicted that loneliness would be associated with poorer CVD values in (1) Japan than the United States (U.S.), (2) in individuals higher rather than lower in collectivism, and (3) our exploratory hypotheses about gender were that loneliness would interact with gender to be associated with differential CVD indicators in the U.S. versus Japan.

METHODS

Participants (aged 36 to 78) from the MIDUS Refresher Biomarker (n = 644) and the MIDJA 2 Biomarker studies (n = 293) completed questionnaires, bloodwork, and a physical exam. U.S. participants were from multiple cities, and Japanese participants were from Tokyo. Loneliness was measured via responses to the question, "How often in the past week did you feel lonely?" Logistic regression and path analyses using structural equation modeling determined individual differences in loneliness, whether loneliness predicted CVD indicators, and whether nationality, collectivism, and gender moderated these associations.

RESULTS

Loneliness was prevalent in the U.S. (25.39%) and Japan (20.82%). Unexpectedly, Japanese adults reported less collectivism than U.S. adults. We found significant interactions of (1) nationality and gender on MetD and inflammation, (2) gender and loneliness on sleep dysfunction, and (3) nationality and loneliness on MetD. Loneliness was associated with greater MetD in the U.S. but not in Japan.

CONCLUSIONS

Cultural influences on loneliness contradicted expectations and suggested caution when equating nationality with cultural values. Our Japanese sample was from Tokyo, which may have lower collectivism than rural Japanese regions. We recommend future studies consider geographic location when examining associations between loneliness, collectivism, and CVD.

A meta-analysis of the association between loneliness and all-cause mortality in older adults

Despite the well-established association between loneliness and all-cause mortality in older adults, it remains unknown whether this association holds for older adults of different sex and whether it is influenced by different samples and study characteristics. Thus, this meta-analysis aims to examine moderators of the association between loneliness and all-cause mortality in older adults. To this end, relevant literature was retrieved from the PubMed, Embase, PsycINFO, Web of Science, Chinese National Knowledge Infrastructure, Weipu, and Wanfang databases (inception to May 2023) and was processed in the Comprehensive Meta-Analysis 3.3 software. Moreover, subgroup analysis was performed to explore the sources of heterogeneity and further explore potential moderators. Funnel plots, Begg's test, and Egger's linear regression test were used to examine the publication bias, and sensitivity analysis was used to test the robustness of the results. Thirty-six studies involving 128,927 older adults were included in this meta-analysis. In general, loneliness was related to an increase in all-cause mortality in older adults (HR = 1.09, 95% CI = 1.06-1.12, I2 = 63.31%, p < 0.001). The overall effect size for older men was 1.18 (95% CI = 1.04-1.33, p = 0.010). The association between loneliness and all-cause mortality was found to be significantly influenced by the source country of the data, follow-up length, and covariates for chronic disease as moderators. In conclusion, loneliness among older adults deserves more attention, and services are needed to improve their mental health.

Estimating the heterogeneous health and well-being returns to social participation

Social participation is defined as an individual's involvement in activities that provide connections with others in society. Past research has demonstrated links between social participation, improved health and well-being, and reduced social isolation, but has been restricted to older people and has not investigated heterogeneity. Using cross-sectional data from the UK's Community Life Survey (2013-2019; N = 50,006), we estimated returns to social participation in the adult population. We included availability of community assets as instruments in a marginal treatment effects model, which allows treatment effects to be heterogeneous and examines whether the effects vary by propensity to participate. Social participation was linked to reduced loneliness and improved health (-0.96 and 0.40 points respectively on 1-5 scales) and increased life satisfaction and happiness (2.17 and 2.03 points respectively on 0-10 scales). These effects were larger for those on low income, with lower education attainment, and who live alone or with no children. We also found negative selection, indicating those less likely to participate have higher health and well-being returns. Future interventions could focus on increasing community asset infrastructure and encouraging social participation for those with lower socio-economic status.

Sense-Making of Loneliness and Exclusion From Social Relations Among Older Adults in Sweden

BACKGROUND AND OBJECTIVES

Loneliness and exclusion from social relations (ESR) are frequently addressed as public health issues for older adults. Public discourses potentially influence how loneliness and ESR are understood in society and experienced by the individual. The aim of this study was to analyze how older adults in different parts of Sweden use the discourses and concepts available to them to describe experiences of ESR and loneliness, and how these descriptions are used to construct a self-identity.

RESEARCH DESIGN AND METHODS

Qualitative semi-structured interviews were conducted with 30 individuals (14 men, 16 women) aged 67-87 years and living in Sweden. Emphasis was, in line with perspectives of discursive psychology, on how individuals draw on discourses to make sense of experiences. The empirical material was analyzed through an inductive process where we were open to finding concepts and themes.

RESULTS

Most participants emphasized the importance of not being lonely, considered achievable through maintaining an active lifestyle. "Othering" was taking place, where a general image of a "lonely" older adult was referred to when speaking about "others" loneliness. Those who expressed feelings of loneliness related these feelings to loss, being omitted, and other difficult life circumstances.

DISCUSSION AND IMPLICATIONS

States of ESR were discussed more comfortably than loneliness, whereas various linguistic resources were used to distance themselves from loneliness. These findings indicate the need for further studies elaborating on how older adults make sense of ESR and loneliness and what implications this has for older adults' well-being and identity making.

The Impact of the COVID-19 Pandemic on Loneliness Among University Students: A Cross-Sectional Study in Jordan

INTRODUCTION

Loneliness is characterized by a sense of melancholy, emptiness, and despair, as well as a higher risk of both psychological and physical problems. Numerous post-coronavirus disease 2019 (COVID-19) sequela, both physically and mentally, have been caused by the global COVID-19 pandemic that has affected many people. Memory issues and loneliness were found to be uniquely correlated. The purpose of this study was to evaluate how the COVID-19 epidemic affected the levels of loneliness among Jordanian university students.

METHODS

This is a cross-sectional questionnaire-based study. Google Forms were used for data collection, utilizing a three-item loneliness scale developed by the University of California, Los Angeles (UCLA), United States, which accounts for the following items: (1) how often does the participant feel about lacking companionship, (2) how often does the participant feel being left out, and (3) how often does the participant feel isolated from others. Each item was marked for three frequency levels of experience: (1) hardly ever, (2) some of the time, and (3) often. Responses to the three loneliness questions were graded on a scale of 3-9, with scores between 3 and 5 indicating "not lonely" and scores between 6 and 9 indicating "lonely."

RESULTS

The study included 802 participating students. Specifically, 75.4% of the participants were females, 58% were aged 20-25, and 39% were 17-19. In addition, 37% were from the capital city, while 28% lived in the middle area. Seventy nine percent were from public universities, and 74% were studying in their second year. According to UCLA's three-item loneliness scale, 411 (51.2%) participants were lonely, while 391 (48.8%) participants were not feeling lonely. According to direct question answers, 576 (71.8%) participants were lonely, and 226 (28.2%) were not lonely.

CONCLUSION

The study concluded that the frequency of loneliness was high among Jordanian university students. However, both genders experienced equal levels of loneliness, while younger participants felt more lonely than older ones.

Age differences in functional brain networks associated with loneliness and empathy

Loneliness is associated with differences in resting-state functional connectivity (RSFC) within and between large-scale networks in early- and middle-aged adult cohorts. However, age-related changes in associations between sociality and brain function into late adulthood are not well understood. Here, we examined age differences in the association between two dimensions of sociality-loneliness and empathic responding-and RSFC of the cerebral cortex. Self-report measures of loneliness and empathy were inversely related across the entire sample of younger (mean age = 22.6y, n = 128) and older (mean age = 69.0y, n = 92) adults. Using multivariate analyses of multi-echo fMRI RSFC, we identified distinct functional connectivity patterns for individual and age group differences associated with loneliness and empathic responding. Loneliness in young and empathy in both age groups was related to greater visual network integration with association networks (e.g., default, fronto-parietal control). In contrast, loneliness was positively related to within- and between-network integration of association networks for older adults. These results extend our previous findings in early- and middle-aged cohorts, demonstrating that brain systems associated with loneliness, as well as empathy, differ in older age. Further, the findings suggest that these two aspects of social experience engage different neurocognitive processes across human life-span development.

Would the Real Loneliness Please Stand Up? The Validity of Loneliness Scores and the Reliability of Single-Item Scores

Several measures that assess loneliness have been developed for adults. Across three studies, we investigated psychometric features of scores of different versions of the Rasch-Type Loneliness Scale, the University of California Los Angeles Loneliness Scale, and three single-item measures. In Study 1 (N = 697 self-ratings, N = 282 informant-ratings of 160 targets) and Study 2 (N = 1,216 individuals from 608 couples), we investigated convergent validity, self-informant agreement, and nomological nets of the item scores using correlates related to demographic aspects, personality, satisfaction, and network characteristics. In Study 3 (N = 411), we estimated a reliability of r x x > . 70 for scores of three single-item measures of loneliness. Overall, scores of all measures and their nomological nets were highly correlated within and across studies, indicating that the scores of the included measures are all reliable and valid. Recommendations for choosing a loneliness measure are discussed.

Mental health and loneliness in Scottish schools: A multilevel analysis of data from the health behaviour in school-aged children study

BACKGROUND

Adolescent loneliness and poor mental health represent dual public health concerns. Yet, associations between loneliness and mental health, and critically, how these associations vary in school settings are less understood.

AIMS

Framed by social-ecological theory, we aimed to identify key predictors of adolescent mental health and examine school-level variation in the relationship between loneliness and mental health.

SAMPLE

Cross-sectional data on adolescents from the 2018 wave of the Health Behaviour in School-aged Children study (HBSC) in Scotland were used (N = 5286).

METHODS

Mental health was measured as a composite variable containing items assessing nervousness, irritability, sleep difficulties and feeling low. Loneliness was measured via a single item assessing how often adolescents felt 'left out'. Multilevel models were used to identify social-ecological predictors of mental health, associations with loneliness and between-school variation.

RESULTS

Loneliness, as well as demographic, social and school factors, was found to be associated with mental health. Mental health varied across schools, with the between-school difference greater among adolescents with high levels of loneliness. Additionally, the negative effect of loneliness on mental health was stronger in schools with lower average mental health scores.

CONCLUSIONS

The findings suggest that schools can play an important role in shaping adolescent mental health. Our study uniquely identifies that school-based interventions targeting mental health may be especially necessary among lonely adolescents, and programmes aimed at tackling loneliness may be more beneficial in schools with poorer mental health.

The association between loneliness and life satisfaction: examining spirituality, religiosity, and religious participation as moderators

BACKGROUND

Future cohort of older adults may have to rely on non-family sources and forms of support, religion being one of them. This may be especially so, considering the recent longitudinal evidence that individuals are inclined to become more religious with increasing age. Thus, the purpose of the present study was to assess the association between loneliness and life satisfaction among older adults in India, and the extent to which the association between loneliness and life satisfaction is moderated by spirituality, religiosity, and religious participation.

METHODS

Data come from the Longitudinal Ageing Study in India, with a sample of 31,464 individuals aged 60 years and above. Multivariable logistic regression models were employed to examine the independent association of loneliness and life satisfaction. Further, an interaction analysis was conducted to examine the extent to which the association between perceived loneliness and life satisfaction is moderated by spirituality, religiosity and religious participation among older Indians.

RESULTS

The prevalence of low life satisfaction (LLS) was 30.84%; a total of 37.25% of participants reported feeling lonely, 12.54% reported a lack of spiritual experience, 21.24% reported not being religious, and 19.31% reported not participating in religious activities. Older adults who felt lonely had higher odds of LLS relative to peers who were not lonely. Further, the adverse impact of loneliness on LLS among older Indians is moderated by their spirituality, religiosity, and religious participation. Specifically, the adverse impact of loneliness on LLS was less negatively pronounced among older adults who were spiritual, religious, and engaged in religious activities.

CONCLUSIONS

The study found an independent association between loneliness and lower life satisfaction among older adults in India. It also revealed that religiosity, spirituality and religious participation moderate the association between loneliness and lower life satisfaction. These findings, which underscore the health promoting benefits of religiosity and religious engagement, may be used to build on the interaction between religious and faith-based groups and public health professionals.

Predictors of Loneliness Among Older Lesbian and Gay People

This study sought to understand the social and individual factors that predict loneliness among older lesbian and gay people in Australia. A sample of 508 gay men and 241 lesbian women, aged 60 and over, completed a survey including measures of loneliness, internalized homonegativity, sexual orientation discrimination, and connectedness to lesbian and gay communities. A multivariable linear regression predicting loneliness was conducted. Not being in an intimate relationship and having less connection to lesbian and gay communities were significant predictors of loneliness for both older lesbian women and gay men. For the men, younger age, internalized homonegativity and more frequent lifetime experiences of sexual orientation discrimination also appeared to predict greater likelihood of loneliness. More frequent recent experiences of sexual orientation discrimination predicted loneliness for the women. The findings confirmed loneliness as an issue of concern among older lesbian and gay people and identified factors amenable to intervention to address loneliness.

Emotional, behavioral, and physical health consequences of loneliness in young adult survivors of childhood cancer: Results from the Childhood Cancer Survivor Study

BACKGROUND

Young adults in the general population are at risk of experiencing loneliness, which has been associated with physical and mental health morbidities. The prevalence and consequences of loneliness in young adult survivors of childhood cancer remain unknown.

METHODS

A total of 9664 young adult survivors of childhood cancer (median age at diagnosis 10.5 years [interquartile range (IQR), 5-15], 27.1 years at baseline [IQR, 23-32]) and 2221 siblings enrolled in the Childhood Cancer Survivor Study completed a self-reported survey question assessing loneliness on the Brief Symptom Inventory-18 at baseline and follow-up (median follow-up, 6.6 years). Multivariable models evaluated the prevalence of loneliness at baseline only, follow-up only, and baseline + follow-up, and its associations with emotional distress, health behaviors, and chronic conditions at follow-up.

RESULTS

Survivors were more likely than siblings to report loneliness at baseline + follow-up (prevalence ratio [PR] 2.2; 95% confidence interval [CI], 1.7-3.0) and at follow-up only (PR, 1.4; 95% CI, 1.1-1.7). Loneliness at baseline + follow-up was associated with elevated risk of anxiety (relative risk [RR], 9.8; 95% CI, 7.5-12.7), depression (RR, 17.9; 95% CI, 14.1-22.7), and current smoking (odds ratio [OR], 1.7; 95% CI, 1.3-2.3) at follow-up. Loneliness at follow-up only was associated with suicidal ideation (RR, 1.5; 95% CI, 1.1-2.1), heavy/risky alcohol consumption (RR, 1.3; 95% CI, 1.1-1.5), and new-onset grade 2-4 chronic conditions (RR, 1.3; 95% CI, 1.0-1.7).

CONCLUSIONS

Young adult survivors of childhood cancer have elevated risk of experiencing loneliness, which is associated with future emotional distress, risky health behaviors, and new-onset chronic conditions.

Sensor-based assessment of social isolation in community-dwelling older adults: a scoping review

Social isolation (SI) is a state of low social interaction with peers associated with various adverse health consequences in older adults living in the community. SI is most often assessed through retrospective self-reports, which can be prone to recall or self-report biases and influenced by stigma. Ambient and wearable sensors have been explored to objectively assess SI based on interactions of a person within the environment and physiological data. However, because this field is in its infancy, there is a lack of clarity regarding the application of sensors and their data in assessing SI and the methods to develop these assessments. To understand the current state of research in sensor-based assessment of SI in older adults living in the community and to make recommendations for the field moving forward, we conducted a scoping review. The aims of the scoping review were to (i) map the types of sensors (and their associated data) that have been used for objective SI assessment, and (ii) identify the methodological approaches used to develop the SI assessment. Using an established scoping review methodology, we identified eight relevant articles. Data from motion sensors and actigraph were commonly applied and compared and correlated with self-report measures in developing objective SI assessments. Variability exists in defining SI, feature extraction and the use of sensors and self-report assessments. Inconsistent definitions and use of various self-report scales for measuring SI create barriers to studying the concept and extracting features to build predictive models. Recommendations include establishing a consistent definition of SI for sensor-based assessment research and development and consider capturing its complexity through innovative domain-specific features.

Screening for loneliness in representative population samples: Validation of a single-item measure

BACKGROUND

Loneliness is a highly relevant public mental health issue. This work presents the validation of a single-item measure of loneliness and its subjective experience: "I am frequently alone/have few contacts". It can be used in large-scale population surveys where an economical assessment is of key importance.

METHODS

Data was drawn from two representative German population surveys conducted in early and late 2020 (combined N = 4,984; 52.9% women; age: M = 48.39 years (SD = 17.88)). We determined the prevalence of loneliness in men and women across different age groups. In order to test concurrent validity, bivariate correlation analyses and Chi-square tests were performed. Convergent and discriminant validity were tested by investigating intercorrelations of the single-item measure of loneliness with another loneliness measure, other mental health outcomes, and associations with sociodemographic characteristics.

RESULTS

Based on the single-item measure, 23.4% of participants reported some degree of loneliness, 3.4% among them severe loneliness. Comparisons with the LS-S showed similar prevalence rates of loneliness. A moderately positive relationship between the two loneliness measures was found by bivariate correlation analysis (ρ = .57, p < .001), but results indicated only weak convergent validity. Construct validity was supported by associations with depressive symptoms, anxiety symptoms, satisfaction with life, household size, and partnership.

CONCLUSIONS

Loneliness is frequently reported in the general population. The single-item measure of loneliness is suitable as a brief screening measure in population-based assessments.

Quality of life and loneliness post-bereavement: Results from a nationwide survey of bereaved older adults

Older people experience bereavements more often than any other age group. National survey data collected across Australia from 633 bereaved adults aged 65+ years showed that 21% met the criteria for prolonged grief. Their quality of life was significantly lower and loneliness significantly higher compared to older people in the general population. Risk factors for the low quality of life and high loneliness post-bereavement included being female, experiencing the death of a partner, and being the full-time carer of the deceased. Time since bereavement, expectedness, and cause of death were not significantly associated with quality of life and loneliness.

Persistent loneliness due to COVID-19 over 18 months of the pandemic: A prospective cohort study

BACKGROUND

Loneliness was common early in the COVID-19 pandemic due to physical distancing measures, but little is known about how loneliness persisted into later stages of the pandemic. We therefore examined longitudinal trajectories of loneliness over 18 months of the pandemic and subgroups at risk for persistent loneliness.

METHODS

We used data from the COVID-19 & Chronic Conditions study collected between March 27, 2020 to December 10, 2021, including 641 predominantly older adults with ≥1 chronic condition who completed six interviews at approximately 3 month intervals. Participants reported loneliness (defined as some, most, or all of the time) during the past week due to COVID-19. We used trajectory mixture models to identify clusters of individuals following similar trajectories of loneliness, then determined subgroups likely to be classified in different loneliness trajectories using multivariable regression models adjusted for sociodemographic and clinical covariates.

RESULTS

Participants were on average 63 years old, 61% female, 30% Black, 20% Latinx, and 29% were living below the poverty level. There was an overall reduction in loneliness over time (March to April/2020: 51% to September to December/2021: 31%, p = 0.01). Four distinct trajectory groups emerged: (1) "Persistent Loneliness" (n = 101, 16%); (2) "Adapted" (n = 141, 22%), individuals who were initially lonely, with feelings of loneliness decreasing over time; (3) "Occasional loneliness" (n = 189, 29%); and (4) "Never lonely" (n = 211, 33%). Subgroups at highest risk of the "Persistently Lonely" trajectory included those identifying as Latinx (aOR 2.5, 95% CI: 1.2, 5.2), or living in poverty (aOR 2.5; 95% CI: 1.4, 4.6).

CONCLUSIONS

Although loneliness declined for a majority of older adults during the pandemic in our sample, persistent loneliness attributed to the COVID-19 pandemic was common (1 in 6 adults), particularly among individuals identifying as Hispanic/Latinx or living in poverty. Interventions addressing loneliness can ease pandemic-related suffering, and may mitigate long-term mental and physical health consequences.

[Resilience in older people during the first wave of the COVID-19 pandemic in Chile: Perspective from the social determinants of health]

OBJECTIVE

To assess the association between social determinants of health (SDH) and resilience in older people during the first period of confinement in the COVID-19 pandemic in Chile.

MATERIALS AND METHODS

An observational study with a cross-sectional design was conducted using a nationally representative survey data-set. In this survey, using a systematic randomization process, a subsample of people aged ≥60 years from the community were interviewed by telephone during the first wave of the COVID-19 pandemic in Chile. Resilience was assessed using the Brief Resilient Coping Scale (BRCS) and depressive symptoms using the Patient Health Questionnaire (PHQ-9) scale. The SDH considered were: age, sex, educational level, employment status, social isolation, loneliness, discontent with housing and health care needs.

RESULTS

A total sample of 582 persons was obtained. The mean age was 71 years (SD: 7.64; 69% women). A significant association was obtained between low resilience and the following conditions: loneliness (OR: 1.776 [95% CI: 1.146-2.751]), high risk of social isolation (OR: 1.667 [95% CI: 1.149-2.419]), and depressive symptoms (OR: 2.602 [95% CI: 1.795-3.774]). Female gender was a protective factor (OR: 0.589 [95% CI: 0.406-0.855]).

CONCLUSION

The SDH, such as loneliness and social isolation, are factors associated with low resilience in older people during the COVID-19 pandemic and may be taken into account in planning public health intervention strategies.

Associations between loneliness and frailty among older adults: Evidence from the China Health and Retirement Longitudinal Study

Background

Previous studies have demonstrated the associations between loneliness and frailty in late life. However, there is a lack of consensus on the direction of the relationship. The present study aimed to examine the interdependencies between loneliness and frailty over time.

Methods

Data on participants aged 60 years old and above were collected from the 2011, 2013, and 2015 samples of the China Health and Retirement Longitudinal Study (CHARLS). Loneliness was measured by a single question from the Centre for Epidemiological Studies Depression scale, and frailty was assessed by the Physical Frailty Phenotype (PFP) scale. Cross-lagged panel models were utilized to examine the potential bidirectional relationship between loneliness and frailty.

Results

Reciprocal associations were found between loneliness and frailty. Furthermore, we found that baseline frailty and early change in frailty had a significant predictive effect on late change in loneliness. Higher baseline loneliness in older adults may create a potentially vicious cycle that influenced early change in frailty and continued to cause late change in loneliness.

Conclusion

A bidirectional relationship may exist between loneliness and frailty among older Chinese adults over 60 years old. Lonely older adults should be alerted to the potential self-reinforcing cycle of loneliness that affects their health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03044-0.

Evaluating Links between Social Withdrawal Motivations and Indices of Psychosocial Adjustment among Norwegian Emerging Adults

Social withdrawal is the behavioral tendency to remove oneself from social situations - a tendency that often contributes to reductions in individuals' mental health. The current study evaluated the links between different motivations for social withdrawal (shyness, unsociability, social avoidance) and indices of psychosocial adjustment in a Norwegian sample of emerging adults. Participants were N = 194 Norwegian university students who completed self-report measures of life satisfaction, loneliness, and depressive symptoms, as well as withdrawal motivations. Among the results, a newly translated version of the Social Preference Scale-Revised (SPS-R) was validated for use in Norway. Findings showed that shyness was uniquely and positively associated with loneliness and depressive symptoms, as well as lower life satisfaction, whereas social avoidance was positively associated with depressive symptoms. Unsociability was uniquely linked to lower levels of loneliness and depressive symptoms. Findings provide novel information about the psychosocial correlates of social withdrawal motivations during emerging adulthood in the under-explored cultural context of Norway. Understanding nuances in the correlates of different motivations may aid in the development of culturally and developmentally sensitive interventions.

Connection Heals Wounds: Feeling Listened to Reduces Speakers' Loneliness Following a Social Rejection Disclosure

Memories of rejection contribute to feeling lonely. However, high-quality listening that conveys well-meaning attention and understanding when speakers discuss social rejection may help them to reconnect. Speakers may experience less loneliness because they feel close and connected (relatedness) to the listener and because listening supports self-congruent expression (autonomy). Five experiments (total N = 1,643) manipulated listening during visualized (Studies 1, 4, 5) and actual (Studies 2, 3) conversations. We used different methods (video vignettes; in-person; computer-mediated; recall; written scenarios) to compare high-quality with regular (all studies) and poor (Study 1) listening. Findings across studies showed that high-quality listening reduced speakers' state loneliness after they shared past experiences of social rejection. Parallel mediation analyses indicated that both feeling related to the listener and autonomy satisfaction (particularly its self-congruence component; Study 5) mediated the effect of listening on loneliness. These results provide novel insights into the hitherto unexplored effect of listening on state loneliness.

Loneliness and personal well-being in young people: Moderating effects of individual, interpersonal, and community factors

INTRODUCTION

Loneliness is prevalent among young people. But, there is little work exploring the association between loneliness with well-being among this age group. Framed by social-ecological theory, we examined demographic, interpersonal, and community factors associated with personal wellbeing and, critically, identified malleable moderators of the relationship between loneliness and well-being that could be targeted in intervention efforts.

METHODS

We used cross-sectional, secondary data from 965 young people (aged 16-24) from the Community Life Survey in England. Loneliness was measured using a single-item direct measure; personal wellbeing was measured through a composite measure containing items assessing happiness, life satisfaction, and a sense that life is worthwhile (α = 0.88). Regression techniques were used to assess associations between individual, interpersonal, and community factors and well-being, and to identify moderators of the relationship between loneliness and well-being.

RESULTS

Loneliness was negatively associated with well-being. Chatting with neighbors and having people to provide help moderated the relationship between loneliness and well-being. Full-time students and those with good physical health had higher well-being while being a carer was predictive of lower well-being. All community variables were strongly associated with increased well-being. Of all interpersonal variables investigated, only having people to count on was associated with increased well-being.

CONCLUSIONS

Our results demonstrate that supportive relationships and close community ties are important for reducing the negative impact of loneliness on youth well-being. Interventions to improve well-being could benefit from targeting these aspects of young people's social and community lives, while acknowledging individual vulnerabilities, such as poor physical health.

Perceived social isolation is correlated with brain structure and cognitive trajectory in Alzheimer’s disease

Both objective and perceived social isolations were associated with future cognitive decline and increase risk of Alzheimer’s disease (AD). However, the impacts of perceived social isolation depending on different clinical stages of AD have not been elucidated. The aim of this study was to investigate the influence of perceived social isolation or loneliness on brain structure and future cognitive trajectories in patients who are living with or are at risk for AD. A total of 176 elderly patients (mean age of 78 years) who had complaint of memory problems (39 subjective cognitive decline [SCD], 53 mild cognitive impairment [MCI], 84 AD) underwent structural MRI and neuropsychological testing. Loneliness was measured by one binary item question “Do you often feel lonely?.” Voxel-based morphometry was conducted to evaluate regional gray matter volume (rGMV) difference associated with loneliness in each group. To evaluate individual differences in cognitive trajectories based on loneliness, subgroup analysis was performed in 51 patients with AD (n = 23) and pre-dementia status (SCD-MCI, n = 28) using the longitudinal scores of Alzheimer’s Disease Assessment Scale-cognitive component-Japanese version (ADAS-Jcog). Whole brain VBM analysis comparing lonely to non-lonely patients revealed loneliness was associated with decreased rGMV in bilateral thalamus in SCD patients and in the left middle occipital gyrus and the cerebellar vermal lobules I − V in MCI patients. Annual change of ADAS-Jcog in patients who reported loneliness was significantly greater comparing to these non-lonely in SCD-MCI group, but not in AD group. Our results indicate that perceived social isolation, or loneliness, might be a comorbid symptom of patients with SCD or MCI, which makes them more vulnerable to the neuropathology of future AD progression.

Loneliness and not living alone is what impacted on the healthcare professional's mental health during the COVID-19 outbreak in Spain

The present study is aimed at exploring the role of loneliness in the healthcare professionals' mental health during the COVID-19 outbreak in Spain. A total of 1,421 healthcare professionals who were in contact with at least one positive COVID-19 patient participated in a cross-sectional online survey from April to June 2020. Mental health was measured with the General Health Questionnaire-12, and loneliness was assessed with the 3-item UCLA Loneliness Scale. More than 80% of participants showed a certain prone to experience mental health problems, and 90% felt that they had not enough workplace protective measures to manage COVID-19 patients. Presence of loneliness was positively related to higher mental health problems after controlling for other covariates. Other factors related to higher mental health problems were a higher COVID-19 risk perception, being in quarantine, checking COVID-19-related news several times a day and having a lower training on managing infectious diseases. Neither living alone, nor supervisor social support, were related to healthcare professionals' mental health. Results suggest that the impact of COVID-19 in terms of mental health in the healthcare professionals could be more related to subjective appraisals of social isolation rather than to be physically alone. There were also a variety of cognitive, behavioural and training-related factors that were associated with the healthcare professionals' mental health, and that should be potentially managed in the mental healthcare interventions.

The Association between Trajectories of Loneliness and Physical Frailty in Chinese Older Adults: Does Age Matter?

Background: The present study aimed to examine age differences in the relationship between trajectories of loneliness and physical frailty among Chinese older adults. Methods: A total of 4618 participants aged ≥60 years old were taken from pooled data created from the 2011−2015 China Health and Retirement Longitudinal Study (CHARLS). Loneliness was assessed by a single question from the Centre for Epidemiological Studies scale, whereas physical frailty (PF) was examined by the physical frailty phenotype scale. We characterized trajectories of loneliness and PF using transition types and changes within the survey period. Results: Logistic regression models revealed that baseline loneliness was significantly related to remaining robust PF (OR = 0.55, 95% CI = 0.49−0.63, p < 0.001) and worsening in PF (OR = 1.17, 95% CI = 1.05−1.30, p < 0.01) at follow-up. Baseline PF status was also significantly related to the transitions in loneliness (worsen: OR = 1.41, 95% CI = 1.11−1.78, p < 0.01; improve: OR = 0.65, 95% CI = 0.47−0.91, p < 0.05). The cross-lagged panel model found that baseline PF or loneliness had a significant predictive effect on the changes in each other. The associations between trajectories of loneliness and PF were weakened with age and clustered in the under 75 age groups. Conclusions: Bidirectional associations may exist between trajectories of loneliness and PF among Chinese older adults. Interventions should mainly target the young-old to reduce the adverse reciprocal effects of loneliness and PF.

Age differences in the association between loneliness and anxiety symptoms during the COVID-19 pandemic

Loneliness and associated mental health problems are of particular concern during the COVID-19 pandemic due to physical distancing and lockdown restrictions. Loneliness is most common among young adults and women during the pandemic, but it is unclear if the association between loneliness and mental health problems, notably anxiety, is strongest in these groups. The objective of this study was to examine whether the association between loneliness and anxiety differed by age and/or gender during the pandemic. We analyzed data from a multi-wave national online survey of Canadians aged 18+ years from May 2020 to March 2021 (n = 7,021). Multivariable modified least-squares regression was used to examine whether the association between loneliness and moderate to severe anxiety symptoms (GAD-7 10+) differed by age and/or gender on the additive scale, controlling for socio-demographic factors, depression, hopefulness, and survey wave. Age significantly moderated the association between loneliness and anxiety symptoms while gender did not. Loneliness was associated with anxiety symptoms for all age groups, but the association was not as strong among those aged 70+ years compared to other age groups. Evidence-based loneliness interventions that target younger adults are needed to mitigate the mental health effects of infectious disease events such as COVID-19.

Evaluation of the Efficacy of Two Internet-based Self-help Interventions for Chronic Loneliness: Study Protocol for a Three-arm Randomized Controlled Trial (Preprint)

Background

Loneliness, or perceived social isolation, is prevalent in both the general population and clinical practice. Although loneliness has repeatedly been associated with mental and physical health, research on interventions that reduce loneliness effectively is still rather scarce.

Objective

This study aims to evaluate the efficacy of a guided and an unguided version of the same internet-based cognitive behavioral self-help program for loneliness (SOLUS-D) for adults.

Methods

A total of 250 participants will be randomly assigned to 1 of 2 intervention groups (SOLUS-D with guidance or SOLUS-D without guidance) or a wait-list control group (2:2:1 allocation ratio). Adult participants experiencing high levels of loneliness will be recruited from the general population. Individuals currently experiencing at least moderately severe depressive symptoms, an ongoing severe substance use disorder, previous or current bipolar or psychotic disorder, or acute suicidality will be excluded from the trial. Assessments will take place at baseline, 5 weeks (midassessment), and 10 weeks (postassessment). The primary outcome is loneliness assessed using the 9-item University of California, Los Angeles Loneliness Scale at the posttreatment time point. Secondary outcomes include depressive symptoms, symptoms of social anxiety, satisfaction with life, social network size, and variables assessing cognitive bias and social behavior. The maintenance of potentially achieved gains will be assessed and compared at 6 and 12 months after randomization in the 2 active conditions. Potential moderators and mediators will be tested exploratorily. Data will be analyzed on an intention-to-treat basis.

Results

Recruitment and data collection started in May 2021 and are expected to be completed by 2022, with the 12-month follow-up to be completed by 2023. As of the time of submission of the manuscript, 134 participants were randomized.

Conclusions

This 3-arm randomized controlled trial will add to the existing research on the efficacy of loneliness interventions. Furthermore, it will shed light on the role of human guidance in internet-based treatments for individuals with increased levels of loneliness and the possible mechanisms of change. If SOLUS-D proves effective, it could provide a low-threshold, cost-efficient method of helping and supporting individuals with increased levels of loneliness.

Trial Registration

ClinicalTrials.gov NCT04655196; https://clinicaltrials.gov/ct2/show/NCT04655196

International Registered Report Identifier (IRRID)

DERR1-10.2196/36358

Determinants of social health trajectories during the COVID-19 pandemic in older adults: the Rotterdam Study

OBJECTIVES

The coronavirus disease-2019 (COVID-19) pandemic and accompanying lockdown restrictions impacted social life significantly. We studied associations of sociodemographic factors, mental and social health markers, and brain structure with social health trajectories during the COVID-19 pandemic.

DESIGN

Prospective longitudinal population-based cohort study.

SETTING

Community-dwelling inhabitants of Rotterdam, the Netherlands.

PARTICIPANTS

Repeated questionnaires including questions on social health were sent to Rotterdam Study participants from April 2020 onwards. Social health data at study baseline were available for 5017 participants (mean age: 68.7 ± 11.3; 56.9% women).

MEASUREMENTS

Determinants were assessed in routine Rotterdam Study follow-up (1990-2020), including global brain volumes in a subset of participants (N = 1720). We applied linear mixed models and generalized estimating equations to quantify associations between determinants and trajectories of loneliness, perceived social isolation and social connectedness over three time points from April 22nd to July 31st 2020.

RESULTS

Loneliness prevalence was 27.9% in April 2020 versus 12.6% prepandemic. Social isolation (baseline mean 4.7 ± 2.4) and loneliness scores (baseline mean 4.9 ± 1.5) decreased over time, whereas social connectedness trajectories remained stable. Depressive symptoms, female sex, prepandemic loneliness, living alone, and not owning a pet were independently associated with lower social connectedness and higher social isolation and loneliness at COVID-19 baseline, but recovery of social health was similar for all determinants. Larger intracranial volume was associated with higher social connectedness.

CONCLUSIONS

Despite baseline differences for specific determinants, older adults showed similar recovery of loneliness and social isolation alongside stable social connectedness over time during the pandemic. Social health is multidimensional, especially during a global health crisis.

Prospective effects of loneliness on frequency of alcohol and marijuana use

BACKGROUND

Loneliness is a widespread problem, with demonstrated negative health effects. However, prospective data on the relationship between loneliness and problematic substance use are lacking, and few studies have examined specific commonplace substances, such as alcohol and cannabis. This study used prospective data from a community sample of US adults with problematic alcohol or cannabis use to examine whether loneliness was a predictor of subsequent increased substance use.

METHODS

Participants (N = 210) were recruited between 05/2016-06/2019 from a New York City medical center. At baseline, 3-month, and 6-month follow-ups, participants completed identical computerized questionnaires. We used generalized estimating equations to assess the average effect of past 2-week loneliness on subsequent number of days of alcohol or cannabis use, controlling for baseline days of use, demographic characteristics, and past 2-week DSM-5 depression.

RESULTS

Compared with individuals who were never lonely, participants with moderate or severe loneliness had a significantly higher frequency of alcohol or cannabis use at the subsequent assessment (β = 0.25 95% CI: 0.08-0.42).

CONCLUSION

Individuals experiencing loneliness at least a few times in the past 2 weeks reported more days of subsequent alcohol or cannabis use compared with individuals who were not lonely. This is cause for concern, as national surveys of US adults indicate increasing rates of loneliness, depression and substance use during the COVID-19 pandemic. These results suggest the need for health care providers to screen for feelings of loneliness and potentially harmful coping behaviors such as substance use, and to offer healthier alternative coping strategies.

OUP accepted manuscript

The purpose of this study was to examine the association between age-friendliness of a city, loneliness and depression moderated by internet use among older people during the coronavirus disease 2019 (COVID-19) pandemic. The survey was from ‘The 2020 Survey of Needs Assessment for a Safe Community and Age-Friendly City’ in Xinyi District, Taipei, which was conducted by face-to-face interviews with community-based older adults who were aged 65 and above from one district of Taipei City from May to June 2020 (n = 335). Partial least square structural equation modeling and the SPSS PROCESS macro were used for data analysis. Two domains of an age-friendly city (housing and community support and health services) were found to be associated with reduced loneliness, while one (respect and social inclusion) was associated with decreased depression. The age-friendliness of cities mitigates depression through moderator (internet use) and mediation (loneliness) mechanisms. Although some age-friendly domains of the city reduced loneliness and depression directly, the age-friendliness–loneliness-depression mechanism held true only for older adults who used the internet and not for nonusers. Maintaining the age-friendliness of an environment is beneficial to mental health, and internet use is a necessary condition to gain optimum benefits from age-friendly initiatives. Policy suggestions are discussed.

Automatic Assessment of Loneliness in Older Adults Using Speech Analysis on Responses to Daily Life Questions

Loneliness is a perceived state of social and emotional isolation that has been associated with a wide range of adverse health effects in older adults. Automatically assessing loneliness by passively monitoring daily behaviors could potentially contribute to early detection and intervention for mitigating loneliness. Speech data has been successfully used for inferring changes in emotional states and mental health conditions, but its association with loneliness in older adults remains unexplored. In this study, we developed a tablet-based application and collected speech responses of 57 older adults to daily life questions regarding, for example, one's feelings and future travel plans. From audio data of these speech responses, we automatically extracted speech features characterizing acoustic, prosodic, and linguistic aspects, and investigated their associations with self-rated scores of the UCLA Loneliness Scale. Consequently, we found that with increasing loneliness scores, speech responses tended to have less inflections, longer pauses, reduced second formant frequencies, reduced variances of the speech spectrum, more filler words, and fewer positive words. The cross-validation results showed that regression and binary-classification models using speech features could estimate loneliness scores with an R 2 of 0.57 and detect individuals with high loneliness scores with 95.6% accuracy, respectively. Our study provides the first empirical results suggesting the possibility of using speech data that can be collected in everyday life for the automatic assessments of loneliness in older adults, which could help develop monitoring technologies for early detection and intervention for mitigating loneliness.

Loneliness, social isolation, and all-cause mortality in the United States

Social isolation and loneliness are both established risk factors for mortality, but it remains unclear how these two conditions interact with each other. We used data from 3975 adults aged 25-74 years who completed self-administered questionnaires (SAQs) for the Midlife in the United States (MIDUS) National Study Wave 2 (2004-2006). Loneliness was measured by asking participants how often they felt lonely. A shortened version of the Berkman-Syme Social Network Index that captured partnerships, friends/family, religious participation, and other forms of social connection was used to assess social isolation. Follow-up for all-cause mortality was censored at the end of 2016. We used progressively adjusted Cox proportional hazard models to examine the mortality risks of loneliness, social isolation, the components of social isolation, and combinations of loneliness and isolation. We adjusted for sociodemographic characteristics in our first models and then added health behaviors and physical and mental health conditions in subsequent models. In the minimally adjusted model, loneliness was associated with higher mortality risk (HR, 1.34; 95% CI, 1.22-1.47), but the association was not significant in the fully adjusted model. Social isolation was significantly associated with mortality in the minimally adjusted model (HR, 1.24; 95% CI, 1.15-1.34) and the fully adjusted model (HR, 1.13; 95% CI, 1.04-1.23). Having infrequent contact with family or friends was the component of isolation that had the strongest association with mortality. Contrary to prior literature, which has found either no interaction or a synergistic interaction between isolation and loneliness, we identified a significant, negative interaction between the two measures, indicating that loneliness and social isolation may partially substitute for one another as risk factors for mortality. Both are associated with a similar increased risk of mortality relative to those who express neither; we find no evidence that the combined effect is worse than experiencing either by itself.

Does unemployment lead to greater levels of loneliness? A systematic review

There is evidence that loneliness and unemployment each have a negative impact on public health. Both are experienced across the life course and are of increasing concern in light of the COVID-19 pandemic. This review seeks to examine the strength and direction of the relationship between loneliness and unemployment in working age individuals, and in particular the potential for a self-reinforcing cycle with combined healthcare outcomes. A systematic search was undertaken in Medline, PubMed, PsycINFO, Embase and EconLit from inception to December 2020. PRISMA reporting guidelines were followed throughout this review, study quality was assessed using the Joanna Briggs Institute checklist and results were summarised in a narrative synthesis. English language studies evaluating the relationship between loneliness and unemployment in higher income western countries were included. Thirty-seven studies were identified; 30 cross-sectional and 7 longitudinal. Loneliness was measured by a direct question or loneliness scale while unemployment was self-reported or retrieved from a national register. A positive association between unemployment and increased loneliness was observed across all studies. Thus, across the life-course a clear yet complex relationship exists between unemployment and greater experience of loneliness. The magnitude of this relationship increases with the severity of loneliness and appears to peak at age 30-34 and 50-59. Logistic regression provided the greatest consistency at statistical significance revealing at least a 40% increase in the likelihood of reporting loneliness when unemployed. Recent longitudinal studies identified in this review found higher levels of loneliness following job loss, but also that loneliness was predictive of unemployment suggesting potential bi-directionality in the relationship. This bi-directionality may create a multiplier effect between loneliness and unemployment to form a self-reinforcing relationship and greater health concerns for those most at risk. Thus, review findings suggest the need for cross-sector awareness and intervention to tackle both loneliness and unemployment.