The COVID-19 global pandemic and subsequent public health social measures have challenged our social and economic life, with increasing concerns around potentially rising levels of social isolation and loneliness. This paper is based on cross-sectional online survey data (available in 10 languages, from 2 June to 16 November 2020) with 20,398 respondents from 101 different countries. It aims to help increase our understanding of the global risk factors that are associated with social isolation and loneliness, irrespective of culture or country, to support evidence-based policy, services and public health interventions. We found the prevalence of severe loneliness was 21% during COVID-19 with 6% retrospectively reporting severe loneliness prior to the pandemic. A fifth were defined as isolated based on their usual connections, with 13% reporting a substantial increase in isolation during COVID-19. Personal finances and mental health were overarching and consistently cross-cutting predictors of loneliness and social isolation, both before and during the pandemic. With the likelihood of future waves of COVID-19 and related restrictions, it must be a public health priority to address the root causes of loneliness and social isolation and, in particular, address the needs of specific groups such as carers or those living alone.

Objectives: To assess whether social isolation, social support, and loneliness are independently associated with health-related quality of life (HRQoL). Method: Retrospective analysis including 10,517 women aged 70–75 years from the Australian Longitudinal Study on Women’s Health (ALSWH). Social isolation, social support (Duke Social Support Index), and loneliness (single item) were investigated for their association with standardised HRQoL (physical [PCS] and mental [MCS] components of the SF-36® questionnaire). Analyses were adjusted for sociodemographic variables and number of medical conditions. Results: Only 3% reported being socially isolated, having low social support and being lonely, and 34% reported being not socially isolated, high social support and not being lonely. Each construct was independently associated with HRQoL, with loneliness having the strongest inverse association (PCS: isolation −0.98, low support −2.01, loneliness −2.03; MCS: isolation −1.97, low support −4.79, loneliness −10.20; p-value < 0.001 for each). Women who were not isolated or lonely and with high social support had the greatest HRQoL (compared to isolated, low social support and lonely; MCS: 17 to 18 points higher, PCS: 5 to 8 points higher). Other combinations of social isolation, social support and loneliness varied in their associations with HRQoL. Conclusion: Ageing populations face the challenge of supporting older people to maintain longer, healthy, meaningful and community-dwelling lives. Among older women, social isolation, low social support and loneliness are distinct, partially overlapping yet interconnected concepts that coexist and are each adversely associated with HRQoL. Findings should be replicated in other cohorts to ensure generalisability across other age groups and men.

Objectives: Explorations of relationships between loneliness and depression have focused on loneliness as a uni-dimensional construct. We hypothesised that reciprocal relationships may exist between depressive symptomatology and social and emotional subtypes of loneliness. Methods: Using data from 373 adults aged over 50, who participated in an observational cohort study, we employed a cross-lagged approach within a Structural Equation Modelling framework, to investigate reciprocal links between depressive symptomatology, and social and emotional loneliness, across two waves of data collection, two years apart (controlling for age, sex, education, comorbidities, social network index, and perceived stress). Results: Both depressive symptomatology and loneliness decreased slightly between waves. Auto-regressive effects were strong for all three variables of interest. Cross-lagged pathways were evident, such that depressive symptomatology at baseline predicted both emotional (β = 0.26, p < 0.05) and social (β = 0.17, p < 0.05) loneliness at follow-up. Neither emotional (β = 0.07, p > 0.05) nor social (β = 0.05, p > 0.05) loneliness at baseline predicted depressive symptomatology at follow-up. Conclusions: Results challenge existing understanding of the associations between loneliness and depression. Further investigation of emotional and social loneliness in individuals with depressive disorders is warranted. Findings are discussed in relation to mechanisms that may explain the relationships observed, and possible implications.