How does loneliness cause death?
You’ve probably heard that loneliness is associated with bad health and premature death. Have you ever wondered why? We’ve got you covered. Check out the diagram below. Click on each box to learn more.
Sones et al. (2021)
Situating social connectedness in healthy cities: a conceptual primer for research and policy
Review
Primary finding: Drawing from contemporary public health and urban planning literature, this paper aims to delineate the concept of social connectedness, including its meaning, measurement, and relationship to neighbourhoods and health. Clarifying social connectedness for urban health research and policy is crucial to interpreting and advancing evidence on its role – both its determinants and impacts – in the development of healthy, sustainable, and resilient cities.
Abell et al. (2019)
Living alone and mortality: more complicated than it seems
Editorial
Primary finding: This editorial discussess the role of socioeconomic position in shaping mortality.
Lim et al. (2020)
Understanding loneliness in the twenty-first century: an update on correlates, risk factors, and potential solutions
Editorial
Primary finding: This review examines current literature to identify either known or emerging risk factors and corelates of loneliness since 2006 and makes specific recommendations in advancing our scientific understanding of loneliness.
Campaign to End Loneliness (2020)
The Psychology of Loneliness: Why it matters and what we can do
Report
Primary finding: This report aims to address the current gap in our understanding of the psychological and emotional aspects of loneliness. We cover the role these play in our ability to form meaningful connections and how this knowledge can inform and improve the support for those experiencing loneliness, particularly chronic and severe loneliness.
Park et al. (2020)
The Effect of Loneliness on Distinct Health Outcomes: A Comprehensive Review and Meta-Analysis
Meta-Analysis
Primary finding: Health outcomes were broadly defined to include measures of mental health (i.e., depression, anxiety, suicidality, general mental health), general health (i.e., overall self-rated health), well-being (i.e., quality of life, life satisfaction), physical health (i.e., functional disability), sleep, and cognition. Loneliness had medium to large effects on all health outcomes, with the largest effects on mental health and overall well-being; however, this result may have been confounded by the breadth of studies exploring the association between loneliness and mental health, as opposed to other health outcomes. A significant effect of gender on the association between loneliness and cognition (i.e., more pronounced in studies with a greater proportion of males) was also observed.
Solmi et al. (2020)
Factors Associated With Loneliness: An Umbrella Review Of Observational Studies
Meta-Analysis
Primary finding: From 210 studies initially evaluated, 14 publications were included, reporting on 18 outcomes, 795 studies, and 746,706 participants. Highly suggestive evidence (class II) supported the association between loneliness and incident dementia (relative risk, RR=1.26; 95%CI: 1.14-1.40, I2 23.6%), prevalent paranoia (odds ratio, OR=3.36; 95%CI: 2.51-4.49, I2 92.8%) and prevalent psychotic symptoms (OR=2.33; 95%CI: 1.68-3.22, I2 56.5%). Pooled data supported the longitudinal association between loneliness and suicide attempts and depressive symptoms. In narrative systematic reviews, factors cross-sectionally associated with loneliness were age (in a U-shape way), female sex, quality of social contacts, low competence, socio-economic status and medical chronic conditions.
Holt-Lunstad et al. (2018)
Why Social Relationships Are Important for Physical Health: A Systems Approach to Understanding and Modifying Risk and Protection
Theoretical Review
Primary finding: Applying the social ecological model, this review highlights the interrelationships of individuals within groups in terms of understanding both the causal mechanisms by which social connection influences physical health and the ways in which this influence can inform potential intervention strategies. A systems approach also helps identify gaps in our current understanding that may guide future research.
Yanguas et al. (2018)
The complexity of loneliness
Theoretical Review
Primary finding: Loneliness is a prevalent and global problem for adult populations, and a number of different studies have linked it to multiple chronic conditions, including: heart disease, lung disease, cardiovascular disease, hypertension, atherosclerosis, stroke, and metabolic disorders, such as obesity and metabolic disease. Is a major predictor of psychological problems, such as depression, psychological stress, and anxiety. Loneliness is linked to overall morbidity and mortality in adult populations.
Leigh-Hunt et al. (2017)
An overview of systematic reviews on the public health consequences of social isolation and loneliness
Systematic Review of Systematic Reviews
Primary finding: Forty systematic reviews of mainly observational studies were identified, largely from the developed world. Meta-analyses have identified a significant association between social isolation and loneliness with increased all-cause mortality and social isolation with cardiovascular disease. Reviews suggest that there is consistent evidence linking social isolation and loneliness to worse cardiovascular and mental health outcomes. The role of social isolation and loneliness in other conditions and their socio-economic consequences is less clear. More research is needed on associations with cancer, health behaviours, and the impact across the life course and wider socio-economic consequences.
Bzdok et al. (2020)
The Neurobiology of Social Distance
Theoretical Review
Primary finding: Over recent years, evidence emerging from various disciplines has made it abundantly clear: perceived social isolation (i.e., loneliness) may be the most potent threat to survival and longevity. We highlight the benefits of social bonds, the choreographies of bond creation and maintenance, as well as the neurocognitive basis of social isolation and its deep consequences for mental and physical health.
Bolmsjo et al. (2019)
Existential loneliness: An attempt at an analysis of the concept and the phenomenon
Theoretical Review
Primary finding: This review explores the role of existential loneliness in facilitating isolation, alianation, emptiness, and abandoment. The authors conclude that in order to meet patients' needs, it is an ethical duty for healthcare staff to be able to recognise experiences of existential loneliness and communicate with the patients about these experiences in an appropriate manner.
Lim et al. (2020)
Understanding loneliness in the twenty-first century: an update on correlates, risk factors, and potential solutions
Theoretical Review
Primary finding: This review provides a review of known and emerging risk factors related to loneliness, focusing ondemography, health, and socio-encironmental factors.
Spithoven et al. (2019)
Genetic Contributions to Loneliness and Their Relevance to the Evolutionary Theory of Loneliness
Theoretical Review
Primary finding: This review provides an updated overview of genetic studies on loneliness and discusses the importance of genetic research for the ETL. The most recent studies suggest that the many genes that contribute to a small degree to differences in loneliness partially overlap with genes that contribute to neuroticism, but not with depression. In addition, the genetic studies discussed in this review show that genes are unlikely to have a direct effect on loneliness. Instead, environmental factors determine in a dynamic fashion how genes that contribute to loneliness are expressed.
Brown et al. (2018)
Loneliness and acute stress reactivity: A systematic review of psychophysiological studies
Systematic Review
Primary finding: the majority of studies reported positive associations between loneliness and acute stress responses, such that higher levels of loneliness were predictive of exaggerated physiological reactions. However, in a few studies, loneliness was also linked with decreased stress responses for particular physiological outcomes, indicating the possible existence of blunted relationships. There was no clear pattern suggesting any sex- or stressor-based differences in these associations. The available evidence supports a link between loneliness and atypical physiological reactivity to acute stress.
Tzouvara et al. (2015)
A narrative review of the theoretical foundations of loneliness
Theoretical Review
Primary finding: Loneliness has been found to relate to a wide range of harmful health outcomes. The adverse effects of loneliness upon people's lives emphasise the importance of understanding its nature and process. A number of theoretical and conceptual foundations have been proposed by scholars and are discussed and reflected upon in this article. The discussion and understanding of loneliness theoretical foundations provide useful insights toward the interpretation of its occurrence.
Goossens et al. (2015)
The genetics of loneliness: linking evolutionary theory to genome-wide genetics, epigenetics, and social science
Theoretical Review
Primary finding: Currently, there is no extant research on loneliness based on genome-wide association studies, gene-environment-interaction studies, or studies in epigenetics. Such studies would allow researchers to identify networks of genes that contribute to loneliness. The contribution of genetics to loneliness research will become stronger when genome-wide genetics and epigenetics are integrated and used along with well-established methods in psychology to analyze the complex process of gene-environment interplay.
Cacioppo et al. (2014)
Evolutionary mechanisms for loneliness
Theoretical Review
Primary finding: Research over the past decade suggests a very different view of loneliness than suggested by personal experience, one in which loneliness serves a variety of adaptive functions in specific habitats. We review evidence on the heritability of loneliness and outline an evolutionary theory of loneliness, with an emphasis on its potential adaptive value in an evolutionary timescale.
Qualter et al. (2015)
Loneliness across the life span
Theoretical Review
Primary finding: The authors review evidence of how aspects of reaffiliation motive change across development and how these aspects can fail for different reasons across the life span. They then conclude with a discussion of age-appropriate interventions that may help to alleviate prolonged loneliness.
Campagne (2019)
Stress and perceived social isolation (loneliness)
Literature Review
Primary finding: Data indicate that both loneliness and solitude may be caused by or correlate with biological factors resulting from psychological (life quality) and medical (health) factors including circulating stress hormones, immune system components and the glutamate system. Causal and correlational links between stress and loneliness are under-researched and study size is generally small. Most research is correlational and study criteria diverse. This review is partly descriptive.
Porcelli et al. (2019)
Social brain, social dysfunction and social withdrawal.
Theoretical Review
Primary finding: Summarizes present knowledge linking neurobiological substrates sustaining social functioning, social dysfunction and social withdrawal in major psychiatric disorders.
Bhatti et al. (2017)
The Pathophysiology of Perceived Social Isolation: Effects on Health and Mortality.
Theoretical Review
Primary finding: There are clear linkages between PSI and the cardiovascular system, neuroendocrine system, and cognitive functioning. PSI also leads to depression, cognitive decline, and sleep problems. The mechanisms through which PSI causes these effects are neural, hormonal, genetic, emotional, and behavioral. The effects of PSI on health are both direct and indirect. There is a complex interconnected network of pathways through which PSI negatively influences health. These hypothetical pathways using which the effects of PSI have been explained form the base on which further analyses can be carried out.
Quadt et al. (2020)
Brain-body interactions underlying the association of loneliness with mental and physical health
Theoretical Review
Primary finding: In this narrative review, the authors provide an overview of published research and related literature describing the manifold interactions between loneliness, affective symptomatology, neural and embodied processing relevant to physical health, mental health, and neurodiversity. They further propose a framework that can inform the identification of psychophysiological mechanisms underlying the link between loneliness and affective symptomatology that may represent interventional targets to mitigate the associated cycle of biopsychosocial morbidity.
Hawkley et al. (2012)
Effects of social isolation on glucocorticoid regulation in social mammals
Theoretical Review
Primary finding: The authors review the effects of social isolation on the functioning of the HPA axis in social species, and on glucocorticoid physiology in social mammals in particular. Evidence indicates that objective and perceived social isolation alter HPA regulation, although the nature and direction of the HPA response differs among species and across age. The inconsistencies in the direction and nature of HPA effects have implications for drawing cross-species conclusions about the effects of social isolation, and are particularly problematic for understanding HPA-related physiological processes in humans.
Cruces et al. (2014)
The effect of psychological stress and social isolation on neuroimmunoendocrine communication
Theoretical Review
Primary finding: The adaptive response to physical or psychological challenges or threats involves the modulation of the three regulatory systems: the nervous, endocrine and immune systems. The disruption of social bonds constitutes a potent emotional stress. Thus, social isolation is considered a risk factor for morbidity and mortality. The response to isolation or loneliness can vary greatly between individuals due to the influence of many factors, some of which will be considered in this Review. These factors can exert a significant influence on the three regulatory systems throughout the lifespan of the organism, and they include characteristics of the stressor itself (e.g., duration), as well as those of the organism (e.g., biological age), in addition to external factors (e.g., environmental events).
Spithoven et al. (2017)
It is all in their mind: A review on information processing bias in lonely individuals
Theoretical Review
Primary finding: The current review provides an up-to-date overview of studies examining loneliness in relation to various aspects of cognitive functioning. These studies are interpreted in light of the Social Information Processing (SIP) model. A wide range of studies indicate that lonely individuals have a negative cognitive bias in all stages of SIP.
Cacioppo et al. (2014)
The neuroendocrinology of social isolation
Theoretical Review
Primary finding: Human and animal investigations of neuroendocrine stress mechanisms that may be involved suggest that (a) chronic social isolation increases the activation of the hypothalamic pituitary adrenocortical axis, and (b) these effects are more dependent on the disruption of a social bond between a significant pair than objective isolation per se. The relational factors and neuroendocrine, neurobiological, and genetic mechanisms that may contribute to the association between perceived isolation and mortality are reviewed.
Eisenberger et al. (2014)
Social pain and the brain: controversies, questions, and where to go from here
Theoretical Review
Primary finding: This review begins by summarizing research supporting the physical-social pain overlap. Next, three criticisms of this overlap model are presented and addressed by synthesizing available research. These criticisms include the suggestions that (a) neural responses to social pain are indicative of conflict detection processes, rather than distress; (b) all negative affective processes, rather than social pain specifically, activate these pain-related neural regions; and (c) neural responses to social (and physical) pain reflect the processing of salience, rather than hurt.
Eisenberger et al. (2012)
The neural bases of social pain: evidence for shared representations with physical pain
Theoretical Review
Primary finding: This review summarizes a program of research that has explored the idea that experiences of physical pain and social pain rely on shared neural substrates. First, evidence showing that social pain activates pain-related neural regions is reviewed. Then, studies exploring some of the expected consequences of such a physical pain-social pain overlap are summarized. These studies demonstrate that a) individuals who are more sensitive to one kind of pain are also more sensitive to the other and b) factors that increase or decrease one kind of pain alter the other in a similar manner. Finally, what these shared neural substrates mean for our understanding of socially painful experience is discussed.
Cacioppo et al. (2011)
Social isolation
Theoretical Review
Primary finding: The effects of perceived isolation in humans share much in common with the effects of experimental manipulations of isolation in nonhuman social species: increased tonic sympathetic tonus and HPA activation; and decreased inflammatory control, immunity, sleep salubrity, and expression of genes regulating glucocorticoid responses. Together, these effects contribute to higher rates of morbidity and mortality in older adults.
Cacioppo et al. (2014)
Toward a neurology of loneliness
Theoretical Review
Primary finding: Experimental studies show that social isolation produces significant changes in brain structures and processes in adult social animals. These effects are not uniform across the brain or across species but instead are most evident in brain regions that reflect differences in the functional demands of solitary versus social living for a particular species. The human and animal literatures have developed independently, however, and significant gaps also exist. The current review underscores the importance of integrating human and animal research to delineate the mechanisms through which social relationships impact the brain, health, and well-being.
Sonderland et al. (2014)
Should social disconnectedness be included in primary-care screening for cardiometabolic disease? A systematic review of the relationship between everyday stress, social connectedness, and allostatic load
Systematic Review
Primary finding: The current evidence strongly indicates that the more socially connected individuals are, the less likely they are to experience chronic stress and associated allostatic load. The negative association between social connectedness and various chronic diseases can thus, at least partially, be explained by the buffering qualities of social connectedness against allostatic load. We argue that assessing social connectedness in clinical and epidemiological settings may therefore represent a considerable asset in terms of prevention and intervention.
Campagne et al. (2019)
Stress and perceived social isolation (loneliness)
Systematic Review
Primary finding: Data indicate that both loneliness and solitude may be caused by or correlate with biological factors resulting from psychological (life quality) and medical (health) factors including circulating stress hormones, immune system components and the glutamate system. Forty years of incidental research give indications as to a co-causal or prodromic role for stress in loneliness.