Social Disconnection in Late Life Mental Illness – Commentary From the National Institute of Mental Health

Abstract

•Social disconnection – both objective social isolation as well as perceived social isolation (otherwise known as loneliness) – is a prevalent affliction among older adults, with profound effects on mental health.•Mechanistic understanding of how mental illness contributes to, is exacerbated by, or is otherwise linked to social disconnection remains elusive, and therapeutic interventions which leverage social connection to enhance compliance with or efficacy of mental health treatment, though promising, remain scarce.•The National Institute of Mental Health (NIMH) is committed to transforming the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery, and cure. To translate basic knowledge into new methods for diagnosis, treatment, and prevention of mental illness demands appreciation for the broader milieu of social and environmental factors in which mental illness prevails – of which, social connection or disconnection is one. Social disconnection – a term which refers to either objective social isolation, perceived social isolation (otherwise known as loneliness), or the co-presence of both – is a prevalent affliction among older adults. Nearly a quarter of older Americans live alone,1Cudjoe TKM Roth DL Szanton SL et al.The epidemiology of social isolation: National Health and Aging Trends Study.J Gerontol Ser B. 2020; 75: 107-113Crossref Scopus (174) Google Scholar,2Hawkley LC Wroblewski K Kaiser T et al.Are U.S. older adults getting lonelier? Age, period, and cohort differences.Psychol Aging. 2019; 34: 1144-1157Crossref PubMed Scopus (54) Google Scholar and surveys suggest that over one third of Americans over the age of 45 are lonely at least some of the time,3Anderson GO Thayer CE Loneliness and Social Connections: A National Survey of Adults 45 and Older.2018Google Scholar with levels of loneliness increasing rapidly among those over the age of 70,4Luhmann M Hawkley LC Age differences in loneliness from late adolescence to oldest old age.Dev Psychol. 2016; 52: 943-959Crossref PubMed Scopus (302) Google Scholar the same age when objective social isolation is highest.5Cornwell B Age trends in daily social contact patterns.Research on Aging. 2016; 33: 598-631Crossref Scopus (71) Google Scholar In the midst of the COVID-19 Global Pandemic, which poses disparate mortality risk for older adults,6Jordan RE Adab P Cheng KK Covid-19: risk factors for severe disease and death.BMJ. 2020; 368: 1-2Google Scholar and public health regulations encouraging physical isolation to protect the most vulnerable populations, the prevalence of abject objective social isolation, as well as feelings of loneliness, are likely to rise. These issues highlight the need for effective strategies and solutions to help alleviate the negative health impacts of social isolation. Social disconnection puts individuals at greater risk for all-cause morbidity and mortality7Holt-Lunstad J Smith TB Baker M et al.Loneliness and social isolation as risk factors for mortality: a meta-analytic review.Perspect Psychol Sci. 2015; 10: 227-237Crossref PubMed Scopus (2419) Google Scholar at a rate greater than or equivalent to traditional health risk factors such as alcohol consumption, physical activity, and obesity.8Holt-Lunstad J Smith TB Layton JB Social relationships and mortality risk: a meta-analytic review.PLoS Med. 2010; 7: e1000316Crossref PubMed Scopus (3807) Google Scholar It also has profound effects on mental health. A commonly reported association exists between loneliness and depression, with some evidence that feelings of loneliness exacerbate later depressive symptoms,9Cacioppo JT Hawkley LC Thisted RA Perceived social isolation makes me sad: 5-year cross-lagged analyses of loneliness and depressive symptomatology in the Chicago Health, Aging, and Social Relations Study.Psychol Aging. 2010; 25: 453-463Crossref PubMed Scopus (969) Google Scholar, 10Jaremka LM Andridge RR Fagundes CP et al.Pain, depression, and fatigue: Loneliness as a longitudinal risk factor.Heal Psychol. 2014; 33: 948-957Crossref PubMed Scopus (172) Google Scholar, 11Jeuring HW Stek ML Huisman M et al.A six-year prospective study of the prognosis and predictors in patients with late-life depression.Am J Geriatr. Psychiatry. 2018; 26: 985-997Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar though the relationships may be bidirectional.12Santini ZI Jose PE Cornwell EY et al.Social disconnectedness, perceived isolation, and symptoms of depression and anxiety among older Americans (NSHAP): a longitudinal mediation analysis.Lancet Public Heal. 2020; 5: e62-e70Abstract Full Text Full Text PDF PubMed Scopus (567) Google Scholar, 13Domènech-abella J Mundó J Maria J et al.Anxiety, depression, loneliness and social network in the elderly: longitudinal associations from The Irish Longitudinal Study on Ageing (TILDA).J Affect Disord. 2019; 246: 82-88Crossref PubMed Scopus (144) Google Scholar, 14Hsueh Y-C Chen C-Y Hsaio Y-C et al.Longitudinal, cross-lagged panel analysis of loneliness and depression among community-based older adults.J Elder Abus Negl. 2019; 31: 281-293Crossref PubMed Scopus (27) Google Scholar Links also exist between social disconnection and a number of other mental illnesses, including anxiety,13Domènech-abella J Mundó J Maria J et al.Anxiety, depression, loneliness and social network in the elderly: longitudinal associations from The Irish Longitudinal Study on Ageing (TILDA).J Affect Disord. 2019; 246: 82-88Crossref PubMed Scopus (144) Google Scholar,15Lim MH Rodebaugh TL Zyphur MJ et al.Loneliness over time: the crucial role of social anxiety.J Abnorm Psychol. 2016; 125: 620-630Crossref PubMed Scopus (157) Google Scholar,16Teo AR Lerrigo R Rogers MAM The role of social isolation in social anxiety disorder: a systematic review and meta-analysis.J Anxiety Disord. 2013; 27: 353-364Crossref PubMed Scopus (86) Google Scholar psychosis,17Chau AKC. Zhu C So SH et al.Loneliness and the psychosis continuum: a meta-analysis on positive psychotic experiences and a meta-analysis on negative psychotic experiences.In Rev Psychiatry. 2019; 31: 471-490Crossref PubMed Scopus (26) Google Scholar,18Rhodes S Vasilopoulou E Hutton P Loneliness in psychosis : a meta-analytical review.Schizophr Bull. 2018; 44: 114-125Crossref PubMed Scopus (123) Google Scholar obsessive compulsive disorder,19Meltzer H Bebbinton P Dennis MS et al.Feelings of loneliness among adults with mental disorder.Soc Psychiatry Psychiatr Epidemiol. 2013; 48: 5-13Crossref PubMed Scopus (165) Google Scholar borderline personality disorder,20Liebke L Bungert M Thome J et al.Loneliness, social networks, and social functioning in borderline personality disorder.Personal Disord Theory Res Treat. 2017; 8: 349-356Crossref Scopus (61) Google Scholar,21Hauschild S Winter D Thome J et al.Behavioural mimicry and loneliness in borderline personality disorder.Compr Psychiatry. 2018; 82: 30-36Crossref PubMed Scopus (18) Google Scholar and post-traumatic stress disorder.22Dagan, Y, Yager, J. Addressing loneliness in complex PTSD. The Journal of Nervous and Mental Disease 2019;207:433–439.Google Scholar,23Kuwert P Knaevelsrud C Pietrzak RH Loneliness among older veterans in the United States: results from the National Health and Resilience in Veterans Study.Am J Geriatr Psychiatry. 2014; 22: 564-569Abstract Full Text Full Text PDF PubMed Scopus (81) Google Scholar Alarmingly, social disconnection – either real or perceived – is also one of the primary risk factors for a suicidal attempt24Calati R Ferrari C Brittner M et al.Suicidal thoughts and behaviors and social isolation : a narrative review of the literature population.J Affect Disord. 2019; 245: 653-667Crossref PubMed Scopus (238) Google Scholar and is one of the primary motivators of self-harm in older adults.25Troya MI Babtunde O Polidano K et al.Self-harm in older adults: Systematic review.Br J Psychiatry. 2019; 214: 186-200Crossref PubMed Scopus (57) Google Scholar Yet mechanistic understanding of how mental illness contributes to, is exacerbated by, or is otherwise linked to social disconnection remains elusive, and therapeutic interventions which leverage social connection to enhance compliance with or efficacy of mental health treatment,26Choi N.G Peppin R Marti CN et al.Improving social connectedness for homebound older adults: randomized controlled trial of tele-delivered behavioral activation versus tele-delivered friendly visits.Am J Geriatr Psychiatry. 2020; https://doi.org/10.1016/j.jagp.2020.02.008Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar,27Solomonov N Bress JN Sirey JA et al.Engagement in socially and interpersonally rewarding activities as a predictor of outcome in “Engage” behavioral activation therapy for late-life depression.Am J Geriatr Psychiatry. 2019; 27: 571-578Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar though promising, remain scarce. As the United States population rapidly ages – within the next 15 years, the number of US adults over the age of 65 are expected to outnumber US children under the age of 18 for the first time in history28US Census BureauOlder people projected to outnumber children for first time in U.S.History. 2018; Google Scholar – issues of social disconnection are becoming more pressing public health issues.29Social Isolation and Loneliness in Older Adults: Opportunities for the Health Care System. National Academies Press, 2020Google Scholar Older adults are disproportionately likely to encounter bereavement, to exit the workforce (i.e., through retirement or layoffs), to endure decreased physical functioning and mobility which can limit in-person social interactions, and to suffer visual and hearing impairments, making telephone, social media, and other digital means of social interaction difficult or impossible. Together, these factors making them more likely to become objectively socially isolated. This can be accompanied by profound loneliness– the discrepancy between the number or quality of relationships that one desires and those that one has.30Peplau LA Perlman D Blueprint for a social psychological theory of loneliness.in: Cook M. Wilson G. Love and Attraction. Pergamon, 1979: 99-108Crossref Google Scholar Yet even in the presence of objective social connection (for instance, when living among family or in an assisted living community), individuals can experience the feeling of loneliness. Indeed, the statistical correlation between loneliness and objective social isolation is relatively weak.31Cornwell EY Waite LJ Social disconnectedness, perceived isolation, and health among older adults..J Health Soc Behav. 2009; 50: 31-48Crossref PubMed Scopus (1165) Google Scholar, 32Hughes ME Waite LJ Hawkley LC et al.A short scale for measuring loneliness in large surveys: results from two population-based studies.Res Aging. 2004; 26: 655-672Crossref PubMed Scopus (1908) Google Scholar, 33Coyle CE Dugan E Social isolation, loneliness and health among older adults.J Aging Health. 2012; 24: 1346-1363Crossref PubMed Scopus (379) Google Scholar Though perceived social isolation (i.e., loneliness) is generally more predictive of individuals’ overall assessment of their mental health than objective social isolation,31Cornwell EY Waite LJ Social disconnectedness, perceived isolation, and health among older adults..J Health Soc Behav. 2009; 50: 31-48Crossref PubMed Scopus (1165) Google Scholar,33Coyle CE Dugan E Social isolation, loneliness and health among older adults.J Aging Health. 2012; 24: 1346-1363Crossref PubMed Scopus (379) Google Scholar measuring both types of social disconnection concurrently and independently is critical.34Perissinotto CM Covinsky KE Living alone, socially isolated or lonely — what are we measuring?.J Gen Intern Med. 2014; 29: 1429-1431Crossref PubMed Scopus (62) Google Scholar Objective and perceived social isolation are independently associated with a number of adverse health outcomes, including poor health behaviors,35Shankar A McMunn A Banks J et al.Loneliness, social isolation, and behavioral and biological health indicators in older adults.Heal Psychol. 2011; 30: 377-385Crossref PubMed Scopus (547) Google Scholar reduced cognitive functioning,36Shankar A Hamer M McMunn A et al.Social isolation and loneliness: relationships with cognitive function during 4 years of follow-up in the English longitudinal study of ageing.Psychosom Med. 2013; 75: 161-170Crossref PubMed Scopus (350) Google Scholar Alzheimer's disease,37Wilson RS Krueger KR Arnold SE et al.Loneliness and risk of Alzheimer disease.Arch Gen Psychiatry. 2007; 64: 234-240Crossref PubMed Scopus (826) Google Scholar and even mortality.7Holt-Lunstad J Smith TB Baker M et al.Loneliness and social isolation as risk factors for mortality: a meta-analytic review.Perspect Psychol Sci. 2015; 10: 227-237Crossref PubMed Scopus (2419) Google Scholar Yet they may also interact to exhibit a synergistic interactive effect, with loneliness being particularly deleterious in the presence of objective isolation and vice versa.38Golden J et al.Loneliness, social support networks, mood and wellbeing in community-dwelling elderly.Int J Geriatr Psychiatry. 2009; 24: 694-700Crossref PubMed Scopus (366) Google Scholar, 39Beller J Wagner A Loneliness, social isolation, their synergistic interaction, and mortality.Heal Psychol. 2018; 37: 808-813Crossref PubMed Scopus (78) Google Scholar, 40Pressman SD Cohen S Miller GE et al.Loneliness, social network size, and immune response to influenza vaccination in college freshmen.Heal Psychol. 2005; 24: 297-306Crossref PubMed Scopus (397) Google Scholar In the context of understanding mental illness trajectories, it is particularly important to measure objective and perceived social isolation independently, as many mental health issues are accompanied by symptoms that may differentially increase the odds of objective or perceived social isolation or that may be differentially impacted by objective or perceived social isolation. Further, the manners in which these different types of social disconnection impact mental illness and the underlying neural circuits relevant for domains of psychopathology may be independent, even if the occurrence of objective and perceived social isolation is not always orthogonal. Future research should address whether and how these distinct forms of social disconnection can thus be targeted through intervention research or leveraged to enhance other mental health interventions. Yet such intervention research must be informed by neurobiological and behavioral mechanistic understanding of how social isolation, loneliness, or their co-occurrence differentially impact mental illness.29Social Isolation and Loneliness in Older Adults: Opportunities for the Health Care System. National Academies Press, 2020Google Scholar The National Institute of Mental Health (NIMH) is committed to transforming the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery, and cure. To carry out that mission, NIMH supports research across the entire translational pipeline, ranging from basic neuroscience, genetics, behavioral science, technology development, or drug discovery to effectiveness research evaluating pharmacological, psychosocial, somatic, rehabilitative and combination interventions for mental and behavioral disorders and mental health services research. The Division of Translational Research (DTR) supports research efforts to translate knowledge from basic science to discover the etiology, pathophysiology, and trajectory of mental disorders across the lifespan and is committed to fostering work that will lead to new discoveries and effective interventions. DTR solicits innovative research projects that integrate knowledge from many levels of analysis (from genomics and circuits to behavior and self-report) to understand basic dimensions of functioning that span the full range of human behavior from typical to atypical, as outlined in the Research Domains Criteria (RDoC) framework.41Insel TR The NIMH research domain criteria (RDoC) project: precision medicine for psychiatry.Am J Psychiatry. 2014; 171: 395-397Crossref PubMed Scopus (935) Google Scholar,42Insel T Cuthbert B M Garvey M et al.Research Domain Criteria (RDoC): Toward a new classification framework for research on mental disorders.Am J Psychiatry. 2010; 167: 748-751Crossref PubMed Scopus (4036) Google Scholar One dimension – social functioning – entails a broad array of social constructs (including perception and understanding of self and others, social communication, and affiliation and attachment) that exhibit substantial heterogeneity in the population. Understanding variability in social functioning, including variability related to perceived social isolation,43Cacioppo JT Hawkley LC Perceived social isolation and cognition.Trends Cogn Sci. 2009; 13: 447-454Abstract Full Text Full Text PDF PubMed Scopus (934) Google Scholar across levels of analysis can provide insights into the etiology and pathophysiology of mental illness. The RDoC framework also promotes a systematic focus on the environment when considering individual neural circuits and functioning, acknowledging that social and physical environment – including the size of one's objective social network – confer both risk and protection for mental illness, but may also be shaped by the nature of mental illness. Finally, the RDoC framework explicitly considers how dimensions of functioning changes across the lifespan, including the impact of aging. This approach to considering social interactions as part of the environmental context is consistent with the strong recognition across NIMH and the National Institutes of Health (NIH) more broadly that social and environmental factors play a critical role in health and health disparities.44Boyce CA Olster DH Strengthening the public research agenda for social determinants of health.Am J Prev Med. 2011; 40: S86-S88Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar, 45Palmer RC Ismond D Rodriquez EJ et al.Social determinants of health: future directions for health disparities research.Am J Public Health. 2019; 109: S70-S71Crossref PubMed Scopus (74) Google Scholar, 46Evans JD Juliano-Bult D Lee SY. Health disparities research in geriatric mental health: commentary from the National Institute of Mental Health.Am J Geriatr Psychiatry. 2015; 23: 655-657Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar A central cross-cutting theme of the NIMH 2020 strategic plan for research (https://www.nimh.nih.gov/about/strategic-planning-reports/index.shtml) (is understanding how environmental influences that vary within and across populations – including social factors – interact with or affect biological systems important in regulating mental processes and other functions of the body. NIMH's commitment to supporting research on the impact of social disconnection on mental health is evidenced by its participation in funding opportunities supporting research on the impact of social connectedness and isolation on health, as well as other efforts to understand emotion regulation throughout the lifespan and its impact on mental health and disease. These include the recent Notice of Special Interest in administrative supplements and urgent competitive revisions for mental health research on the 2019 Novel Coronavirus, which lists as areas of special interest the interactions between stress and social isolation on symptomatology, as well as research to identify potential intervention targets for modifying social connectedness, isolation, and/or loneliness via social media and/or electronic communication to prevent the development of clinically significant mental health symptoms (NOT-MH-20-047). NIMH also participates in funding opportunities led by the Office of Behavioral and Social Sciences Research (OBSSR) that address “Research on Biopsychosocial Factors of Social Connectedness and Isolation on Health, Wellbeing, Illness, and Recovery” (NOT-OD-20-103). The Geriatrics and Aging Processes Research Branch within DTR supports research to better understand the etiology, pathophysiology, and course of mental disorders of late life, the relationships between aging and mental disorders, the treatment and recovery of persons with aging-related mental disorders, and the prevention of these disorders and their consequences. To translate basic knowledge into new methods for diagnosis, treatment, and prevention of mental illness demands appreciation for the broader milieu of social and environmental factors in which mental illness prevails – of which, social connection or disconnection is one. As this special issue highlights, the mental health impacts, consequences, and correlates of social isolation are evolving areas of science. Important issues remain to be addressed, and the NIMH is committed to supporting this area of research. All authors (EAN, LMR, JDE) contributed to the writing this commentary and approve of its publication. The authors declare no conflicts of interest. There are no financial disclosures to report.