The Psychology of Social Isolation and Loneliness in Later Life

Introduction

Social isolation and loneliness (SIL) have garnered increasing attention as significant public health and clinical concerns,¹ particularly in the context of aging.² While some argue that older adults are disproportionately affected by these conditions due to challenges associated with aging, this review proposes a different rationale for focusing on the psychological implications of SIL in later life: aging is associated with both socioemotional strengths that can protect against SIL as well as biopsychosocial challenges that can increase risk for chronic SIL and amplify its negative effects. As well, social relationships remain malleable across the lifespan, as compared to many aging-related health conditions and impairments that are less amenable to direct intervention, indicating that SIL may be a potent intervention target for healthy aging. This review aims to synthesize the current literature on SIL in older adults through the lens of psychological processes at play in SIL in older adults within the context of lifespan development. By exploring these issues, we seek to highlight clinically actionable intervention targets and areas in need of future study.

Social isolation and loneliness, though often used interchangeably, are distinct constructs. Loneliness refers to the subjective feeling of being socially disconnected, regardless of the actual size or frequency of one’s social network.³ It involves a perceived gap between desired and actual social relationships, which can lead to emotional distress. In contrast, social isolation is an objective measure, characterized by limited social contact, a lack of engagement in social activities, or small social networks.⁴ An individual can be socially isolated without feeling lonely and vice versa. Given these constructs are associated and share similar (though not identical) health outcomes, we consider both together as SIL.⁵ When discussing only one of the constructs, we will use the terms loneliness or social isolation.

Older adults are selective in their social networks in later life and experience greater satisfaction in relationships than younger counterparts.⁶ Evidence suggests healthy older adults experience less loneliness than earlier developmental stages.⁷ However, older adults who experience age related challenges or chronic conditions are at risk for SIL, which can further exacerbate poor mental and physical health outcomes. Studies estimate that approximately 37% of older adults experience significant loneliness, while nearly 34% are socially isolated.² As well, some data suggest that SIL is more likely to become chronic in later life, emphasizing the need for prevention, and when SIL is present, potentially more aggressive intervention strategies. Finally, older adults may experience greater impacts from the experience of SIL, leading to increased healthcare utilization, poorer health outcomes, and higher healthcare costs.⁸

Research on SIL in older adults has evolved significantly over the past few decades. Early studies in the mid-20th century focused on social relationships as protective factors for mental health, laying the groundwork for subsequent investigations into the adverse effects of SIL.⁹ In geriatric mental health, this field gained momentum with the recognition that these social factors are closely linked to depression (and other mental health conditions), worse physical health (including cardiovascular diseases), functional and cognitive decline, and mortality.¹⁰

Psychological models of SIL

Several psychological models of SIL in later life have been proposed to describe factors that cause and maintain SIL in later life. Many of these models draw on lifespan developmental theories that describe growth and development across the lifespan. Box 1 briefly describes available models of SIL in later life as well as lifespan development theories that are referenced in these models.

Box 1. Psychological Models and Lifespan Developmental Theories Relevant to SIL in Later Life.

	Premise and Core Constructs	Theory Focus
Cognitive Behavioral Model (Cacioppo & Hawkley, 2009)	Maladaptive cognitions (hypervigilance to rejection and threat) and social avoidance maintain loneliness and lead to chronicity.	SIL (all ages)
Differential Investment of Resources Model (Huxhold & Fiori, 2024)	Unmet expectations for social relationships in later life at three levels leads to loneliness: close confidants are expected to provide social support and intimacy; broader network members are expected to provide fun and time spent together; the community is expected to provide experiences of respect and generativity. The experience of loneliness is more likely to persist in later life (chronicity).	SIL & Lifespan development
MODEL—Model of Depression and Loneliness (Cohen-Mansfield & Parpura-Gill, 2007)	Barriers to social engagement common in later life increase risk for loneliness: environmental factors/resources, health factors, psychological factors, stressful life events	SIL in later life
Selective Optimization with Compensation Theory (Baltes & Baltes, 1990)	Healthy (or successful) aging results from the (flexible) use of three strategies to adapt to aging-associated changes in health and function: selecting achievable goals, optimizing available function, and compensating for limitations.	Lifespan development
Social Convoy Model (Antonucci, Ajrouch, & Birditt, 2013)	Close relationships ‘travel’ with individuals over time and across developmental stages, constituting a social convoy. Characteristics of convoys impact health and well-being.	Lifespan development
Social Relationship Expectations Framework (Akhter-Khan, Prina, Wong, Mayston, & Li, 2023)	Lifespan developmental theories specify contextual factors that impact core drivers of loneliness in later life—relational motives, expectations, and coping strategies. Unmet expectations of relationships that may lead to loneliness include proximity (availability of others), support (feeling cared about), intimacy (feeling understood), fun (shared pleasant experiences), generativity (meaningful contributions), and respect (valued, mattering, included).	SIL & Lifespan development
Socioemotional Selectivity Theory (Carstensen, Isaacowitz, & Charles, 1999)	Aging is associated with greater prioritization of social and emotional goals (versus knowledge-focused goals), commonly resulting in greater relationship satisfaction and emotional well-being with increasing age.	Lifespan development

Many models of SIL in later life are cognitive behavioral models that emphasize the role of thoughts (cognitions), behaviors (actions), and feelings (physiology) in response to social interactions (including prior and anticipated interactions and expectations) in determining whether someone experiences SIL in a given moment.¹¹ Van Orden and colleagues’ conceptualization of the cognitive behavioral model of SIL in later life¹¹ (Figure 1) was developed to inform intervention. It specifies that, as with emotional states such as depressed mood and anxiety, loneliness can be conceptualized as being caused and maintained not just by ‘objective’ circumstances (e.g., isolation due to inability to leave the home), but also by thoughts (e.g., cognitive distortions, perceptions of social threat), behaviors (e.g., social engagement, isolation, withdrawal), and physiological responses (e.g., stress responses). Inherent to the model is the premise that social isolation, as an objective indicator, is captured by the behavior component of the model and can be directly targeted to increase engagement with people and activities. In contrast, momentary experiences of loneliness (e.g., “I feel lonely right now”) are cognitive-affective experiences that are directly caused by one’s subjective perceptions (or cognitive interpretations), such as thinking of oneself as ‘unlovable’ or ‘alone in the world.’ Thus, the cognitive-behavioral model posits that changing loneliness is most effective via intervening on behavior, physiology or cognitions. In this way, behavioral interventions that promote social activities can be expected to result in change in social isolation first and loneliness second.

Figure 1.

The Cognitive Behavioral Model of SIL in Later Life

Cacioppo’s model of loneliness (Box 1) was designed to describe loneliness and etiological processes. It emphasizes cognitive behavioral processes that occur in response to loneliness that could have an underlying adaptive (evolutionary) advantage.^4,12 Much like hunger motivates an individual to seek food, Cacioppo posits that loneliness motivates social behavior because humans have a ‘need to belong’ to social groups and relationships.^4,13 As a social species, we depend on relationships with others to survive and thrive. Cacioppo’s model posits that isolation from others will lead to loneliness, which is distressing and sets in motion a set of cognitive behavioral responses that, in the short term, may lead an individual to seek connections with others, including increased attention to social cues. Imagine an older person who relocated to a senior living community in a new city to be closer to adult children. Faced with separation from friends and long-standing activities, she began feeling lonely every day. If the older person responded by looking for opportunities to spend time with others and was successful in finding and engaging in such activities, loneliness may remit. However, if initial efforts are not successful, a self-propagating cycle of maladaptive cognitions—including hypervigilance to social threat, attentional and memory biases (of rejection and threat), and negative affect in social situations—may emerge that serves to maintain loneliness and result in chronic SIL, which in most cases, is harmful to the individual.⁷ Imagine the older person who moved to the senior living community had hearing loss that she was previously able to cope with in her prior environment. In the communal dining room, however, she was unable to hear well enough to engage in conversations and felt left out. She assumed that others believed she was being rude by staying quiet and then felt anxious around others. She then started eating her meals in her room alone and loneliness became chronic.

Cognitive neuroscience investigations of loneliness have supported the role of cognitive control, the ability to regulate thoughts, emotions, and behaviors in goal-directed ways, as a key feature in loneliness that may account for negative psychological outcomes,¹⁴ including chronicity. There are few studies examining whether loneliness does in fact motivate social behavior in later life; one study of older adults found a signal that among older women, the experience of loneliness was associated with subsequent increases in engagement with friends, while for men, loneliness was associated with subsequent withdrawal.¹⁵ Research has clearly documented, however, that the negative effects of loneliness are greater for chronic versus transient loneliness among older adults.^16,17

The distinction between chronic and transient loneliness is typically assessed via longitudinal studies that measure loneliness using a self-report questionnaire, such as the UCLA Loneliness Scale or the De Jong Gierveld Loneliness Scale, both of which assess the degree of loneliness experienced by individuals in general. In a typical study, these assessments are done several times over the course of years, with transient and chronic loneliness differentiated by whether loneliness was reported at one, some, or all assessment time points.^16,17 An additional distinction regarding the duration of loneliness is between state (or momentary) loneliness and trait (or general) loneliness. Momentary loneliness refers to the experience of loneliness in a given moment and is often captured via ecological momentary assessment in which research subjects report on how they feel at that time (e.g., “In this moment, I feel lonely”). Momentary assessments of loneliness can also use assessments such as the UCLA Loneliness Scale that do not use the word lonely to reduce the impact of stigma on reporting but often use shortened versions of such scales (e.g., 3-item UCLA Loneliness Scale) to reduce participant burden. Momentary loneliness can be studied by using the level of loneliness reported at one moment to predict outcomes concurrently or at a subsequent point. Momentary loneliness can also be studied by averaging scores across EMA assessment points to capture the average level of momentary loneliness. In contrast, trait loneliness is typically assessed via retrospective self-report of loneliness in general, without a specified time frame. Of note, trait loneliness can change over time (traits are enduring but not immutable), but these changes are thought to reflect shifts in more enduring experiences, comparable to changes in symptoms of a depressive disorder over time. Changes in trait loneliness can represent, for example, the impacts of spousal bereavement, retirement, or relocation on situational loneliness, which could resolve via active coping in these times of transitions – potentially representing social resilience – thereby preventing the onset of chronic loneliness. Research is also beginning to document potential deleterious outcomes of greater momentary loneliness, which could represent potential mechanisms whereby loneliness impacts health, such as more frequent experiences of anxiety¹⁸ and greater inflammation.¹⁹ Taken together, research suggests that momentary, situational, and chronic loneliness are all associated with negative health outcomes, with greater severity and chronicity linked to worse outcomes.^20–21 Distinguishing between these experiences of loneliness can illustrate points for intervention. We return to issues of chronicity and intervention targets later in this article.

Cognitive-behavioral models of loneliness in later life also emphasize aging-specific risk and protective factors^22,23 and the role of adult development²⁴ in causing/maintaining loneliness. Cohen-Mansfield and Parpura-Gill²² proposed a theoretical model of loneliness in older adults—MODEL (Model of Depression and Loneliness; Box 1)—focused on how and why loneliness is associated with depressive symptoms, especially among older adults with fewer environmental resources. The model’s premise is that despite aging-associated strengths in socio-emotional well-being, four types of challenges common in later life introduce challenges to social networks and relationships that must be navigated in order to prevent the development of loneliness and its sequalae—1) environmental factors/resources (e.g., limited finances, limited social opportunities), 2) health factors that impact the ability to socially engage (e.g., fatigue, incontinence, mobility challenges), 3) psychological factors that limit quality social engagement (e.g., limited social skills, reliance on others for social planning, low social self-efficacy), and 4) stressful life events associated with aging (bereavement, retirement, relocation). stressors common in later life (e.g., bereavement, illness).

Akhter-Khan and colleagues²⁴ proposed the Social Relationship Expectations Framework (Box 1), which considers loneliness in later life through the lens of four influential lifespan developmental theories that address social relationships over the life course (See Box 1: Differential Investment of Resources Model²⁵; Social Convoy Model²⁶; Socioemotional Selectivity Theory²⁷; Selective Optimization with Compensation Theory²⁸) as well as Cacioppo’s cognitive behavioral model and key social ecological contextual factors (e.g., poverty, culture). Akhter-Khan’s model proposes that these lifespan developmental theories describe the context in which loneliness may (or may not) develop in later life, including social network changes described by the Convoy Model and future time perspective described by Socioemotional Selectivity Theory. These contextual factors influence the core drivers of loneliness in this model—relational motives, expectations, and coping strategies—that then impact appraisal of current relationships to determine whether loneliness develops. The theory also proposes specific expectations of relationships that influence whether an older adult’s appraisal of his/her relationships are satisfactory or insufficient (i.e., loneliness): proximity (availability of others), support (feeling cared about and supported), intimacy (feeling understood and listened to), fun (shared, enjoyable experiences), generativity (meaningful contributions), and respect (feeling valued, mattering, included), with the latter two especially salient for older adults. Huxhold and Fiori²³ propose the Differential Investment of Resources Model (Box 1), which posits that expectations about relationships are key drivers of loneliness in later life, with unmet expectations in close confidants, social networks, and community involvement increasing risk for loneliness.

SIL in Later Life: A Psychological-Developmental Model

We propose to build on these models of SIL in later life to synthesize both aging related strengths and vulnerabilities for SIL (and its chronicity) and describe mechanisms whereby the impacts of SIL on health may be magnified in later life, even if SIL is not necessarily more common in later life. Existing models focus of SIL in later life focus more on factors accounting for the development of SIL. Our focus, also includes consideration of mechanisms underlying chronicity and consequences of SIL. Our premise, in line with existing data and theory from lifespan developmental theories, is that later life, as a developmental stage, is associated with both risk and resilience factors for SIL and that the presence and chronicity of loneliness is determined (in part) by the balance of risk and resilience factors, as well as responses to an older person’s SIL by other people and an older person’s capacity to flexibly adapt to stressors in a useful way (i.e., ‘adaptive capacity,’). Figure 1 illustrates these concepts and their interplay. We discuss each in turn below.

Protections against SIL.

The normative developmental trajectory in later life is towards greater emotional well-being in environments in which older adults have sufficient resources to meet their needs.²⁹ Lifespan developmental theories and associated research reliably document that increasing age is associated with better emotion regulation in the face of everyday (common) stressors,⁶ including increased attentional control (to positive cues),³⁰ better capacity and use of cognitive appraisal/re-appraisal,³¹ and adaptive coping behaviors.³² This enhanced emotion regulation results in more frequent experience of positive emotions and greater relationship satisfaction (among other indices of aging-related socioemotional strengths).³³ Socioemotional selectivity theory posits that a greater awareness of the finite nature of life shifts older adults’ priorities towards emotionally-meaningful goals, leading to increased prioritization on close relationships and quality relationships.²⁷ Older adults accumulate life experience, self-knowledge, and wisdom that can also protect against SIL in the context of stressors.³⁴ Despite changes in social networks associated with aging, including decreased size of non-family networks, older adults report greater satisfaction with their relationships and networks than younger adults.³⁵ Each of these aging-associated socioemotional strengths has the potential to protect against the development of SIL in the face of stressors and developmentally-expected changes in social networks and roles.

Vulnerabilities to SIL.

As at any life stage, older adults face vulnerabilities to SIL. Those common to later life include social role transitions, such as retirement, losses (including bereavement), caregiving, and end-of-life concerns. As well, chronic illnesses become more common with increasing age and are often accompanied by functional, cognitive, and sensory impairment, as well as the day-to-day challenges of managing medical conditions. In this section, we discuss three such vulnerabilities that have been posited to be especially potent challenges to adaptive capacity in later life because they can produce chronic, unpredictable, and pervasive stress²⁸—caregiving, cancer, and cognitive decline.

Caregiving.

The role of caregiving in exacerbating loneliness and social isolation is significant, as caregivers often face high levels of stress, burnout, and emotional distress. The demands of caregiving—particularly for individuals with chronic illnesses like cancer or ADRD—can leave caregivers with limited time and energy for social connection, leading to SIL.^36–38 Caregiver burden has been extensively studied, with research emphasizing the emotional and social toll caregiving takes on an individual.³⁹ Caregivers, particularly those of spouses or parents with dementia, often experience higher levels of depression, anxiety, and loneliness.⁴⁰ The isolation caregivers experience is often compounded by the emotional toll of seeing their loved one’s health decline, which can lead to a sense of helplessness and detachment from social networks. Interventions aimed at alleviating caregiver isolation have shown some promise.⁴¹ One study demonstrated that caregiver training programs and respite care—providing caregivers with temporary relief from their responsibilities—could reduce feelings of isolation and improve mental health outcomes.⁴² Additionally, programs that provide emotional support through peer counseling or caregiver support groups have been shown to mitigate loneliness and enhance caregivers’ coping strategies.⁴³ These interventions provide avenues to address loneliness and social isolation for caregivers of older adults with chronic conditions.

Dementia and cognitive decline.

Alzheimer’s Disease and related dementias (ADRD) introduce unique challenges regarding SIL due to cognitive decline and the associated loss of communication and interaction. This cognitive decline can lead to withdrawal from social activities, making it more difficult for patients to engage with family members and friends. However, most studies find that SIL precedes cognitive decline and ADRD, versus decline/ADRD leading to SIL (see section on Cognition below). For example, Amano and colleagues examined the time after an initial diagnosis of ADRD and did not find subsequent changes in social engagement and social support.⁴⁴ Some research also suggests that SIL in later life could present as a neuropsychiatric symptom signaling preclinical ADRD, as loneliness has been shown to be associated with greater amyloid burden in cognitively healthy older adults.⁴⁵

Cancer.

Older adults with cancer face unique psychosocial challenges, which are compounded by the social isolation that often accompanies both the illness and its treatments.⁴⁶ Cancer diagnoses in older adults frequently lead to diminished physical abilities, reduced participation in social activities, and disrupted social roles, all of which increase feelings of isolation.⁴⁶ Treatment regimens, such as chemotherapy and radiation therapy, can further exacerbate physical limitations, leaving patients vulnerable to feelings of loneliness.⁴⁷ Additionally, older patients with cancer often face the challenge of losing social support networks. As they cope with the realities of aging and cancer, they may lose peer networks, experience grief over the loss of loved ones, or become distanced from family members who may not fully understand their health needs.⁴⁸ One study found that older patients with cancer who experienced social isolation had higher rates of depression and lower quality of life.⁴⁷ These findings highlight the need for targeted interventions that address the psychosocial needs of patients with cancer, focusing on enhancing social support and minimizing isolation during treatment.

Experience of SIL.

The balance of protective and vulnerability factors experienced by an older person impacts the overall likelihood that they will experience SIL in the context of their social relationships. Many older adults possess emotion regulation skills that allow them to respond adaptively to momentary SIL to prevent the development of more enduring experiences of SIL. For those without such skills or who experience stressors that overwhelm their ability to cope, day-to-day experiences that result in momentary SIL may result in situational SIL lasting for days to weeks, and then to chronic SIL lasting months or more. In the next section, we describe aging-related factors that place older adults at heightened risk for chronic SIL.

Maintaining Factors in SIL

Reduced adaptive capacity to chronic, intense stressors.

Adaptive capacity refers to the ability to respond in a flexible and useful manner to environmental stressors and may be especially relevant to understanding healthy aging.⁴⁹ While older adults typically demonstrate improved emotion regulation, as the body ages, its physiological capacity to flexibly adapt to stressors decreases.²⁸ Emotion regulation refers to the cognitive and behavioral strategies individuals use to manage emotional experiences, which often improve with age due to greater life experience and refined coping mechanisms. In contrast, physiological flexibility in response to stressors involves autonomic, neuroendocrine, and inflammatory processes that can contribute to heightened vulnerability to stress-related health outcomes. Older adults tend to possess greater skill with emotion regulation skills that involve avoiding or preventing the experience of intense negative emotion (and the associated physiological arousal that accompanies it), but when those strategies are unsuccessful and intense negative emotion is experienced, older adults often fare less well than younger adults. Older adults demonstrate reduced physiological flexibility and reduced capacity to regulate intense and prolonged emotional arousal. Thus, while older adults may prevent many instances of prolonged emotional arousal (via greater emotion regulation), some instances may be beyond their control or exceed their capacity for emotion regulation, resulting in a greater impact of stress on emotional, physical, and cognitive function.²⁸ For example, the compounded and chronic burden of older adult caregivers providing physical and emotional care for their loved one while also managing stressors within their own life could overwhelm their ability to regulate emotions because such stressors are unavoidable, leading to prolonged distress, increased physiological stress responses, and potential declines in physical and cognitive health. The Strength and Vulnerability Integration model (SAVI)²⁸ posits that ‘threats to belonging’ are one type of stressor most likely to lead to age-associated vulnerabilities to inadequate physiologic flexibility. This suggests that older adults may be more vulnerable to chronic loneliness than younger adults if the experience of loneliness (i.e., decreased or low belonging) is intense. If this is the case, preventing loneliness, or detecting and treating loneliness before it becomes chronic, may be an especially potent approach to health promotion in later life.

Dyadic Considerations for SIL.

SIL extend their effects beyond the individual, significantly impacting dyadic (pairs) relationships, particularly among older couples and caregiving partnerships. Studies have shown that loneliness experienced by one partner often correlates with increased loneliness and psychological distress in the other, creating a feedback loop that magnifies relational strain.^50,51 The dyadic outcomes of SIL in older adults are critical to understanding how social relationships, particularly those between partners or caregivers and their loved ones, influence mental and physical health. Loneliness does not only affect individuals in isolation but also has profound effects on those in close relationships. The dynamics of these relationships often shape how both partners experience and cope with feelings of loneliness, which can significantly impact mental health, well-being, and even life expectancy.

Impact on Close Relationships.

Loneliness in older adults effects the perceptions of relationship quality in marital and close partnerships.⁵² Studies have shown that one partner’s loneliness can exacerbate emotional distress for the other, contributing to relationship strain. For example, one study found that older adults who reported feeling lonely were more likely to experience marital dissatisfaction, which in turn worsened their mental health and quality of life.⁵³ The perception of loneliness in one partner can be reciprocated, leading to a cycle of emotional distress in the relationship. Similarly, evidence suggests that spousal loneliness is linked to poorer mental health outcomes, particularly depression, which can strain communication and intimacy, thereby worsening the isolation felt by both partners.⁵⁴ Additionally, loneliness in close relationships is associated with the decline in the quality of caregiving. Caregivers, when feeling socially isolated or unsupported may experience burnout, which negatively impacts both their well-being and the well-being of those they care for.⁵⁵ This finding emphasizes the interdependence of SIL and relationship quality in older adults, suggesting that effective interventions must consider dyadic health rather than focusing solely on the individual.

Chronicity.

As discussed above, the greatest health impacts appear to be associated greater chronicity of loneliness. The model we proposed here suggests that older adults may be particularly vulnerable to chronic loneliness aging-associated factors that can create a cycle of maintaining factors: lower adaptive capacity, enduring relational stressors (e.g., family caregiving), and network members who are also older and vulnerable to chronic loneliness (dyadic effects). These ideas are reflected in the right panel of Figure 2.

Figure 2.

The Roles of Protective Factors, Vulnerabilities, and Maintaining Factors in Social Isolation and Loneliness (SIL) in Later Life.

Note. The balance between an older adult’s protective factors and vulnerabilities influences their risk for social isolation and loneliness (SIL; left panel). Maintaining factors (right panel), lead to reduce capacity regulating responses to SIL, increasing risk for chronicity and greater breadth and depth of health impacts.

Effects of SIL on Mental, Physical Health, and Cognitive Health

Mental Health.

SIL are critical determinants of mental and physical health in older adults.⁵⁶ Evidence consistently shows strong associations between these states and adverse mental and physical health outcomes, including heightened risks of depression, anxiety, suicidal ideation, and mortality.⁵⁷ A meta-analysis of studies on older adults revealed that those experiencing high levels of loneliness were twice as likely to develop depressive symptoms.⁵⁸ A 12-year longitudinal study found a strong association between loneliness and depressive symptoms among adults aged 50 and older, underscoring the persistence of loneliness as a predictor of depression over time.⁵⁹ Similarly, indices of social isolation--limited social networks and poor social support—increase risk of depression in community-dwelling older adults.⁶⁰ Beyond mere associations, the interplay between SIL and depression appears to be bidirectional, with loneliness exacerbating depressive symptoms and depression, in turn, intensifying loneliness. This cyclical relationship highlights the importance of timely interventions.⁶¹ Additionally, meta-analyses have shown that loneliness significantly heightens the risk of developing depressive disorders, even when controlling for factors such as physical health and socioeconomic status.⁶²

SIL are not only associated with depressive disorders but also significantly impact anxiety disorders in older adults, with chronic isolation compounding stress and exacerbating emotional vulnerability.⁵⁸ In a sample of 57–85 year olds, a longitudinal mediation analysis examined associations between ‘perceived isolation’ and ‘social disconnectedness’ (i.e., an objective measure of social isolation) with both depression and anxiety symptom severity. The social isolation measure included items assessing social network size, frequency of social interaction, number of friends, number living in the home, socializing with friends and family, attendance at group meetings, and volunteering. The perceived isolation measure included items measuring instrumental support from family friends, and partners, as well as three items assessing loneliness (lack of companionship, feeling left out, isolated). Results indicate that ‘social disconnection’ predicted higher perceived social isolation, which also predicted anxiety severity and depression severity. The study also found the reverse relationships were significant, demonstrating bidirectional relationships.⁶³ Studies show that chronic loneliness can exacerbate feelings of unease, worry, and fear, often leading to generalized anxiety disorder (GAD) and social anxiety disorder (SAD). The subjective distress of loneliness, when persistent, creates a cycle of social withdrawal and heightened vigilance, further compounding anxiety symptoms.⁵⁸ A systematic review highlighted that older adults experiencing high levels of loneliness are more likely to develop GAD, as loneliness often magnifies the perception of social threats and personal inadequacy.⁶⁴

The experience of SIL influence many factors of depression and anxiety, experiences that are also linked with suicidal ideation. Older adults, particularly older men, experience the highest suicide rates in the United States, with suicide risk rising with advancing age, reaching its peak in late life.^65,66 Moreover, older adults reporting both loneliness and isolation exhibit higher rates of suicidal ideation, especially in contexts of chronic illness, limited mobility, and reduced social opportunities.⁶⁷ Evidence suggests that older adults who report SIL are more likely to experience suicidal thoughts and behaviors.^68,69 One study found a strong association between loneliness and increased suicidal ideation, emphasizing that social disconnectedness exacerbates feelings of hopelessness and despair.⁷⁰ Additionally, chronic social isolation, which often results in reduced interpersonal interactions and limited social networks, has been linked to a heightened risk of suicidal behaviors.⁷¹ The absence of meaningful social interactions can lead to feelings of worthlessness and despair, which significantly contribute to the likelihood of suicidal thoughts and actions.⁶⁹

Physical Health.

Several studies have documented the negative impact of SIL on cardiovascular health. One study found that loneliness was associated with increased blood pressure and elevated cortisol levels, which are known to be risk factors for hypertension and heart disease.⁷² The findings suggests that lonely individuals may experience heightened stress responses, contributing to the onset of cardiovascular diseases. In a longitudinal study of older adults, those who were socially isolated had a significantly higher risk of developing coronary heart disease compared to their more socially engaged peers.⁷³ Another study examined the relationship between social isolation and the progression of cardiovascular diseases and found that individuals who experienced chronic loneliness were more likely to develop conditions such as hypertension and myocardial infarction.⁷⁴ The mechanisms behind this association are believed to involve both direct physiological responses (e.g., elevated blood pressure and inflammatory markers) and indirect factors, such as poor health behaviors in isolated individuals.

SIL is also linked to decreased mobility and functional decline in older adults,⁷⁵ including difficulty with activities of daily living, a greater likelihood of experiencing falls. Sedentary behaviors in response to social isolation in older adults can exacerbate functional declines.⁷⁶ Additionally, isolated older adults may have fewer opportunities for physical activity, due to reduced motivation or limited social support to engage in exercise or other health-promoting behaviors.⁵⁰

Cognition.

Social isolation and loneliness (SIL) are associated with poorer global cognitive performance,^77,78 decline in cognitive function over time,^16,79–84 and incident dementia diagnoses.^85–90 SIL is one of 12 modifiable risk factors for dementia identified by the Lancet Commission on Dementia Prevention, which together, are estimated to account for 40% of dementia cases, with SIL accounting for as many cases as late-life depression, and more than physical inactivity, air pollution, and diabetes.⁹¹ Having strong social connections was associated with a 46% reduced likelihood of developing dementia in one prospective study.⁹²

Mortality.

SIL have been consistently linked to increased morbidity and mortality. In a large meta-analysis, both loneliness and social isolation were associated with a 26% and 29% increased risk of premature death, respectively.⁷³ This effect is particularly concerning in older adults, who are already at higher risk for chronic health conditions. The study showed that the risk of mortality was comparable to other well-established risk factors, such as smoking and obesity. A similar study reported that socially isolated individuals had significantly higher rates of hospitalization and longer recovery times.⁹ These findings emphasize the need for public health interventions targeting social connectivity as a means of reducing the risk of premature death and improving the quality of life in older adults.

Discussion

The proposed conceptual model of SIL in later life integrates aging-related strengths and vulnerabilities to provide a comprehensive understanding of how psychological processes in SIL affect health and well-being. Unlike earlier assumptions that SIL is more common in later life, this model underscores that while the prevalence of SIL may not necessarily increase with age, its health impacts can be more pronounced due to aging-related changes in biological, psychological, and social functioning. Building on lifespan developmental theories, the model identifies later life as a stage of heightened risk for SIL due to factors such as the loss of loved ones, declines in health and mobility, and shifts in social roles and community engagement. However, it also recognizes the resilience inherent in older adulthood, including enhanced emotional regulation, accumulated coping skills, and the ability to derive meaning from life transitions. The presence and chronicity of loneliness are conceptualized as being determined, in part, by the dynamic balance between these risk and resilience factors, as well as by an individual’s ‘adaptive capacity’

Social isolation reduces opportunities for cognitive stimulation, emotional support, and meaningful social interaction, thereby accelerating cognitive decline and diminishing emotional well-being. Biologically, SIL activates stress-related pathways (e.g., heightened cortisol and inflammation), which exacerbate physical health challenges such as cardiovascular disease, frailty, and immune dysregulation. Socially, isolation reduces access to instrumental support, creating a feedback loop where reduced social functioning further entrenches loneliness. Over time, these interlocking declines in physical, cognitive, and social functioning reinforce the chronicity of loneliness, making it more resistant to change. By focusing on three key points of intervention—mitigating risk factors (e.g., reducing bereavement-related isolation), strengthening resilience (e.g., promoting emotional regulation and meaning-making), and enhancing adaptive capacity (e.g., fostering coping flexibility)—this model provides a comprehensive framework for disrupting the cycle of loneliness chronicity and promoting well-being in later life.

A growing body of research has explored a range of interventions to address SIL in older adults.⁹³ We propose that effective interventions target three key pathways: 1) prevention at critical transition points by mitigating risk factors, 2) disruption of chronicity by strengthening resilience, and 3) reduction of the impact of SIL on health and well-being by enhancing adaptive capacity.

First, prevention efforts could focus on periods of heightened vulnerability, such as bereavement, retirement, caregiving or relocation, by providing proactive support to maintain social connections (prevent isolation) and promote adaptive coping in response to momentary experiences loneliness, as well as preventing situational loneliness from progressing to chronic. Friendly calling to older adults during the COVID-19 pandemic was associated with reduced loneliness,⁹⁴ which may have worked by addressing momentary loneliness in a period of heightened vulnerability due to social distancing restrictions. As another example, a brief behavioral psychotherapy grounded in behavioral activation reduced loneliness in homebound older adults⁹⁵ and a similar intervention reduced loneliness in dementia caregivers,⁹⁶ both of which may have addressed vulnerability factors associated aging.

Second, to disrupt the chronicity of loneliness, interventions can strengthen resilience to cope with maintaining factors, including functional, cognitive, and relational declines that perpetuate SIL, such as hypervigilance to social threat. An example of one such approach is mindfulness training, which promotes acceptance and compassion and has been shown to reduce loneliness and distress in older adults.⁹⁷

Interventions that target dyads and that are provided in groups have also been studied for SIL in later life given the importance of addressing SIL within the context of relationships. These interventions may work by targeting relational dynamics that serve to maintain SIL. Dyadic interventions target both partners simultaneously, aiming to improve relationship dynamics and reduce SIL. One study suggests that dyadic interventions, including joint therapy or shared activities, can significantly reduce depressive symptoms and improve relationship satisfaction.⁹⁸ For example, interventions that involve shared activities such as hobby-based socialization or mindfulness exercises for couples have been shown to help partners reconnect, fostering emotional closeness and reducing loneliness for both individuals. Life Review Therapy is another dyadic intervention model that serves to promote relationship quality and communication in dyads, which has been tested in older couples experiencing distress due to chronic illness or caregiving roles.⁹⁹ The study found that dyads of older adults with advanced cancer and their caregivers found a dyadic intervention to be feasible and acceptable. Additionally, older adults had clinically meaningful reductions in loneliness, while caregivers had improved perceived dyadic adjustment to stressors. Studies have also examined effectiveness of structured social activities for older dyads, such as group discussions or shared fitness programs, which have been linked to reduced levels of loneliness.¹⁰⁰ These interventions are particularly effective in nursing home settings, where older adults are often less integrated into their communities and may feel lonely as a result. Through such programs, couples and close relationships can develop new routines and social networks, and disrupting a cycle of SIL.³⁵

Finally, interventions can reduce the negative health impacts of loneliness, even if chronic loneliness itself is not fully alleviated, by addressing both maintaining factors and promoting adaptive capacity. Life Review therapy is an evidenced-based mental health intervention that supports emotional processing and self-integration, improving adaptive capacity for managing stressors.⁹⁸ Brief behavioral therapy that facilitates social re-engagement among older adults experiencing SIL demonstrated reductions in isolation and improvements in depression symptoms and increased quality of life, despite no differences in loneliness (versus care as usual).¹⁰¹ It is also possible that interventions might be able to impact momentary loneliness more rapidly than trait loneliness, especially if loneliness is chronic. However, clinical trials have not clearly identified which forms of loneliness are most amenable to intervention, which forms might change first, nor if changing one form of loneliness is more beneficial than another. These are areas in need of study.

Finally, in considering the psychological processes in SIL and their application to interventions, it is necessary to consider that older adults are embedded within social structures, cultures, and historical cohorts. Cultural and societal shifts have shaped the experience and prevalence of SIL among older adults. The increasing mobility of younger generations, urbanization, and the decline of multigenerational households have contributed to greater physical separation from family and community. Technological advances, while offering new means of communication, may not fully compensate for the loss of in-person social interactions for some older adults. Moreover, cultural norms around aging and independence influence how loneliness and isolation are perceived and addressed. In individualistic societies, there is a greater emphasis on self-reliance, which may stigmatize seeking help for loneliness. In contrast, collectivist cultures often emphasize familial and community interdependence, potentially offering more built-in social support.¹⁰²

Conclusion

This scoping review has synthesized current literature on the psychological and physical implications of loneliness and social isolation in older adults, highlighting the profound impact these factors have on mental and physical health, as well as the specific challenges faced by older adults dealing with chronic diseases and caregiving responsibilities. As discussed, loneliness and social isolation are not only associated with depression, anxiety, and suicidal ideation, but they also contribute to a range of physical health issues, including increased morbidity and mortality risks. The conceptual model of SIL in later life offers a comprehensive framework for understanding how aging-related risks and resilience factors shape the presence and chronicity of SIL. This model highlights how SIL reduces physical, cognitive, and social functioning through mechanisms such as heightened stress reactivity, cognitive under-stimulation, and diminished access to social support, which together contribute to a self-reinforcing cycle of SIL chronicity.

The implications for practice are significant. Clinicians, mental health counselors, and community organizations must recognize the multi-faceted nature of loneliness and isolation in older adults and adopt comprehensive approaches to care. This review highlights the value for clinicians to assess older adults’ quality of social supports and experiences of loneliness and social isolation. Quality assessment in older adults could provide a vital point of intervention to prevent the implications of loneliness and isolation highlighted in this review. Interventions must not only address the physical health aspects but also focus on improving social engagement and support systems. For instance, mental health professionals should consider integrating strategies to alleviate loneliness within psychotherapy and counseling sessions, using family or dyadic interventions where appropriate. Community organizations can play a vital role by creating social support networks and offering programs that facilitate social engagement and reduce isolation among older adults, particularly those with chronic conditions like cancer or dementia.

Future research should continue to explore the complex relationships between loneliness, social isolation, and chronic disease in aging populations. Specifically, there is a need for further research into culturally tailored interventions that can address the varying ways in which different populations experience and respond to isolation. Additionally, research into the effectiveness of dyadic interventions, such as those targeting both patients and caregivers, is needed to understand the best practices for mitigating the negative outcomes associated with loneliness and isolation. Gaps remain in understanding the long-term effects of loneliness on physical health outcomes and in identifying novel approaches for prevention and treatment in both clinical and community settings.

By advancing a comprehensive understanding of the psychological dimensions, mechanisms, and intervention points for SIL in older adults, this review underscores the critical need for targeted, mechanism-driven interventions to mitigate chronic loneliness and its profound impact on older adults’ mental, physical, and social well-being.

Synopsis:

This scoping review examines the psychological implications of social isolation and loneliness (SIL) in older adults, emphasizing risk and resilience factors. SIL is linked to mental health issues (depression, anxiety, cognitive decline) and physical health risks (cardiovascular disease, mortality). The review proposes a conceptual model highlighting the balance between protective factors (emotional regulation, wisdom) and vulnerabilities (role transitions, chronic illness) that influence SIL’s chronicity. Interventions should focus on prevention during life transitions, disrupting chronic loneliness, and mitigating health impacts. The review underscores the need for targeted strategies to bolster adaptive capacity in older adults.

Key points:

• Social isolation and loneliness (SIL) in older adults pose significant public health challenges, contributing to increased risks of mental health disorders, cognitive decline, chronic illness, and mortality. Vulnerabilities in later life (ie. Illness, caregiving, role transitions) can contribute to chronicity of SIL.

• SIL is associated with poor mental health outcomes in older adults.

• Interventions bolstering adaptive capacity could reduce chronic SIL.

Clinics Care points.

• The public health implications of SIL in older adults are substantial.

• Vulnerabilities in later life (ie. Illness, caregiving, role transitions) can contribute to chronicity of SIL.

• SIL is associated with poor mental health outcomes in older adults.

• Interventions bolstering adaptive capacity could reduce chronic SIL