Uncovering the impact of loneliness in ageing populations: a comprehensive scoping review

Abstract

Background

Europe’s aging population increasingly faces social isolation and loneliness, with nearly 20% of older adults living alone. Social isolation refers to an objective lack of social contact, while loneliness is the subjective experience of unmet social needs. Both are prevalent among community-dwelling older adults, driven by life transitions, loss, and declining health. These issues severely impact mental and physical health, increasing risks of depression and suicidal ideation. This scoping review maps the literature, identifies knowledge gaps, and highlights key challenges regarding loneliness and social isolation in this population.

Methods

A scoping review was conducted between March and September 2024, following the PRISMA guidelines for scoping reviews. The review adhered to Arksey and O’Malley’s five-stage framework, which includes identifying research questions, searching for and selecting relevant studies, extracting data, and synthesizing results. The search was conducted in major scientific databases, including Embase, CINAHL Plus, Web of Science, and PsycINFO, along with grey literature sources, including doctoral theses and organizational reports.

Results

A total of 45 studies were included, with 66.6% using quantitative methods, 11.1% using qualitative methods, and the remainder being systematic reviews or mixed-method analyses. The studies revealed a significant prevalence of loneliness and social isolation among community-dwelling older adults, with risk factors including health deterioration, widowhood, and loss of social networks. The consequences of loneliness and isolation span physical and mental health issues, including an increased risk of cardiovascular disease, anxiety, depression, and cognitive decline.

Conclusions

Loneliness and social isolation among community-dwelling older adults are complex issues with profound implications for physical, mental, and social well-being. Addressing these challenges requires integrative approaches that consider individual, relational, and contextual factors. Further longitudinal and standardized research is needed to improve our understanding of the long-term impacts and effectiveness of interventions to mitigate these issues.

Background

Social isolation and loneliness in older adults

Europe is undergoing a demographic shift, with a steadily ageing population and a growing number of older adults living alone. This trend is driven by several sociodemographic factors, including declining birth rates, increasing life expectancy, and evolving family structures. Cultural shifts towards individualism and the fragmentation of traditional community-based living arrangements as life expectancies increase have further exacerbated social isolation and loneliness among older adults [1]. According to Eurostat, nearly 20% of people aged 65 and over in the European Union live alone, a figure that continues to rise. A survey by Age UK revealed that 1.2 million older adults in the UK are chronically lonely, a statistic likely mirrored in other European countries [2]. This increasing prevalence of solitude reflects deeper societal changes, including urbanization, smaller family units, and the migration of younger generations to cities. As societies become more individualistic, the support networks that once offered companionship and care for the elderly are weakening, leaving many older adults at risk of prolonged social isolation. According to recent findings of the Generations and Gender Survey, loneliness was common among 30–55% of older people in Central and Eastern Europe and 10–20% in Northwestern Europe [1, 3].

Although often used interchangeably in common discourse, social isolation and loneliness represent distinct concepts within the scientific literature. Social isolation is defined as an objective state characterized by a quantifiable reduction in social contacts and interactions. This can be assessed through measures of social network size, frequency of communication, and participation in social activities. In contrast, loneliness is a subjective emotional experience arising from a perceived discrepancy between desired and actual social relationships. Crucially, the experience of one does not necessitate the presence of the other; individuals can be socially isolated without feeling lonely, and conversely, feel lonely despite maintaining active social connections [4]. This independence underscores the need for differentiated assessment and intervention strategies targeting each phenomenon. Several studies have shown that among older adults, although many may be objectively socially isolated, only a proportion experience loneliness. This suggests that loneliness and social isolation, although related, are not identical experiences and can occur independently of one another [4,5,6].

According to the World Health Organization (WHO), social isolation occurs when an individual has minimal or no contact with others, and it typically involves a lack of meaningful relationships. Social isolation is an objective condition characterized by a lack of social interactions, contacts, and relationships. It involves minimal engagement with family and friends and reduced participation in community or social activities [7]. Social isolation can result from several factors, including physical distance from others, limited mobility, or a lack of social support systems. Unlike loneliness, which is a subjective feeling, social isolation is measurable through concrete indicators such as the number of social contacts or the frequency of social interactions [8].

In contrast to social isolation, loneliness is a subjective emotional experience. It occurs when there is a perceived discrepancy between the quantity and quality of social relationships a person desires and what they experience [9]. Loneliness can occur even in the presence of social interactions if those interactions do not meet an individual’s emotional or social needs. As described by De Jong Gierveld and Van Tilburg (2010), loneliness is a subjective, negative experience that arises when individuals perceive a gap between the social connections they wish to have and those they possess [10]. This means that a person can feel lonely even if they are surrounded by others. Although loneliness can be experienced at various stages of life, it becomes particularly significant in older adulthood because of the accumulation of multiple factors.

Loneliness is a prevalent situation that has been linked to various negative physical and mental health outcomes [11,12,13]. Old age represents a transition often marked by various negative social and health challenges, which can significantly contribute to feelings of loneliness. Life changes associated with ageing, such as the weakening of family and social connections due to children leaving home; the loss of a spouse, parent, or friend; and a decline in health or ability, can make older individuals especially vulnerable to loneliness. Loneliness among older adults has been recognized as a substantial risk factor for suicidal ideation, particularly when loneliness is perceived as unwanted and enduring [14,15,16]. The absence of social support systems and meaningful interpersonal connections has a detrimental effect on mental health, increasing susceptibility to depressive symptoms, which may subsequently precipitate suicidal thoughts. Empirical evidence indicates that, in advanced age, perceptions of being a burden to others and a diminished sense of purpose are associated with reduced resilience to psychological stressors, thereby intensifying the risk of suicidal ideation in the context of chronic loneliness [17].

Common risk factors include widowhood, living alone, deteriorating health, and significant life events such as loss and bereavement. Protective factors include having a confidant and higher socioeconomic status [18].

Loneliness and social isolation in community dwellings

While loneliness and social isolation have been the subjects of considerable research, a definitive understanding of their prevalence, scope, and sequelae within the population of community-dwelling older adults remains incomplete. This demographic, defined as individuals aged 65 years and older residing independently in non-institutional settings such as private residences, exhibits heightened vulnerability to social isolation owing to factors including, but not limited to, age-related declines in mobility, attrition of social networks through mortality or relocation, and the social and economic consequences of retirement. Consequently, community-dwelling older adults represent a critical target population for investigations into the detrimental health outcomes associated with social disconnection.

Considering the impact and importance of loneliness and social isolation, the objective of this research was to synthesize published articles on the phenomenon of loneliness in older adults in community dwellings. Specifically, the goals of this research include the following: (a) identify and map the key factors related to loneliness, main sources of evidence, and research gaps; (b) detect evidence of the consequences of loneliness and social isolation; and (c) capture the diversity of study designs, methodologies, and types of evidence available, including grey literature; (d) determine whether a full systematic review is feasible or necessary; and (e) help researchers identify variables and select appropriate methodologies for future studies by identifying common research approaches and methods used in the literature.

Methods

Study design

Accordingly, a scoping review was conducted between March and September 2024. This review was designed in accordance with the PRISMA guidelines for scoping reviews [19] and followed the five-stage framework outlined by Arksey and O’Malley (2005), which includes (1) identifying the research questions; (2) identifying relevant studies; (3) selecting studies; (4) data charting; and (5) collating, summarizing, and reporting results [20].

In contrast to systematic reviews, which seek to answer specific research questions through detailed and often quantitative analyses, scoping reviews pursue broader objectives and are exploratory in nature. Consequently, this scoping review was not registered in PROSPERO [21]. To ensure the comprehensiveness and accuracy of the search strategy, it was validated by a librarian with expertise in systematic reviews and database searches. Also, the protocol was validated by an external expert in the field prior to the implementation of the search strategy. Additionally, the review protocol was registered in the Open Science Framework (Registration DOI: https://doiorg.publicaciones.saludcastillayleon.es/10.17605/OSF.IO/M9QH5).

Identifying the research questions

The research questions guiding this scoping review were as follows: (1) What are the key concepts related to loneliness in older adults, and what are the primary sources of evidence on this topic? (2) What are the documented consequences of loneliness and social isolation in older adults? (3) What study designs, methodologies, and types of evidence, including grey literature, are available in the research on loneliness among older adults? (4) Is a full systematic review on loneliness in older adults feasible or necessary? (5) What common variables and methodologies in the literature can guide future research on loneliness in older adults?

Identifying relevant information

The search strategy was conducted in two parallel stages. First, a systematic search was performed using major scientific databases, including Embase, CINAHL Plus, Web of Science, and PsycINFO. Second, additional searches were performed in sources of grey literature, such as doctoral thesis databases (Teseo, TDX, DART, OATD) and the websites of national and international organizations. It also included a manual search to add relevant information related to the main topic of the investigation.

To construct the search strategy, relevant keywords were identified for the main variables: loneliness and older adults. The concept of “loneliness” included related terms such as isolation, solitude, and social isolation, whereas “older age” encompassed variations such as elder, old age, and elderly. The terms within each variable were combined using the OR operator, and the main variables were connected using the AND operator. For reproducibility, the search strategy including the databases searched and the main keywords used was: (isolation OR Loneliness OR Solitude OR social isolation) AND (aged OR aging or ageing or elder* OR “old age” OR “old* people”) AND (mental health OR emotional OR physical health OR health problems OR chronic diseases OR frailty OR health outcomes).

Study selection

The selection process was guided by predefined inclusion and exclusion criteria to ensure alignment with the study objectives. The inclusion criteria were as follows:

• Focus: Studies investigating community-dwelling older adults (65 years or older).

• Phenomenon: Research addressing loneliness and social isolation specifically.

• Language: Publications in English or Spanish.

• Publication Date: Studies published between 2013 and 2024.

• Source Type: Peer-reviewed journals, doctoral theses, reports, conference proceedings, books, and government publications.

The exclusion criteria were as follows:

• Focus Misalignment: Studies that did not focus on the topic of loneliness or social isolation in older adults.

• Accessibility: Documents for which the full text was unavailable, despite requests made to authors.

The selection process began with an initial screening of titles and abstracts to assess relevance, followed by a full-text review of studies that met the initial criteria. Two independent reviewers conducted each stage of the selection process to maintain consistency and reduce bias. Any disagreements between reviewers were discussed and resolved through consensus to ensure that all selected studies aligned with the review’s objectives.

Charting the data

This phase was executed by the reviewers in three distinct phases to ensure accuracy, consistency, and comprehensiveness in data handling.

• Phase 1: Initial screening and identification of duplicates. The first step involved an independent review of the titles and abstracts by each reviewer on the basis of the preestablished inclusion and exclusion criteria. Studies that met the initial relevance criteria were subjected to a full-text review. During this phase, duplicates across different databases were identified and removed to avoid redundancy in the final dataset.

• Phase 2: Collaborative review and removal of duplicates. Following the independent reviews, the selected records were shared among all reviewers for a collaborative evaluation. Duplicates identified across the different databases were removed, and only those records that adhered to the study’s objectives and inclusion criteria were retained for further analysis. This collaborative review process helped ensure the consistency and reliability of the selected studies.

• Phase 3: Final selection of records. In this phase, only those studies that were agreed upon by all reviewers were included in the final set for analysis. This consensus-based approach ensured the validity and relevance of the selected studies to the research questions and the objectives of the scoping review.

The retrieved articles were transferred to the Covidence review manager for screening and review [21]. In the data extraction process, a comprehensive range of key concepts and main consequences related to loneliness was systematically extracted from each study. These variables included bibliographic details, participant characteristics (age and gender), the geographical context of the study, the data collection methods employed, the consequences and the specific factors related to loneliness that were investigated. Standardized charting was employed to ensure consistency across studies and to facilitate data analysis. Additionally, Table 3 presents the main findings from the studies, which should be considered when extrapolating the data and conclusions of this review.

Collating, summarizing, and reporting the results

In this final phase, the findings were synthesized to identify prevalent themes, research gaps, and methodological trends in the literature. Key insights from both the scientific literature and the grey literature were combined to present a comprehensive overview of the current research landscape on loneliness among older adults.

Results

To illustrate the strategy and the results of the search, the study flowchart is presented (Fig. 1).

Fig. 1

PRISMA flow diagram of study selection process

Characteristics of the included studies

Among the 52 studies, 40 (76.6%) used quantitative methods (27 cross-sectional, 9 cohort studies, and 2 experimental, 2 longitudinal), 4 (16%) were qualitative, 3 (5.7%) were systematic or scoping reviews, and 4 (16%) applied mixed methods or opinion-based analyses, and 1 case report. Geographically, 20 (44,4%) studies were from Europe, 14 (31,1%) were from Asia, 6 (13,3%) were from the United States or Canada, 2 (4,4%) were from Latin America, and 3 (6,6%) were from regions such as Australia and Ghana. In total, 24 (54,4%) studies were conducted in community settings, followed by 8 (17,7%) virtual studies (including telephone interviews, online platforms, virtual support groups, mail, and WhatsApp), 4 (8,8%) in health care units, and 3 (6,6%) each in residential and institutional settings. Sample sizes varied from 7 to 35,878 participants, totalling over 150,000. Table 1 presents the detailed characteristics of the included studies.

Table 1 Characteristics of the studies

Of the 28 grey literature documents (Table 2), 15 were doctoral theses, followed by reports [3] and final academic projects [4]. The majority, 17 (51,8%), originated from Spain, with others from New Zealand, Oman, the US, the Netherlands and Canada.

Table 2 Grey literature

The studies included in this review were conducted across a wide range of settings, as summarized in Table 1. These settings include community-based environments, where 24 studies were conducted, reflecting the increasing focus on understanding loneliness in everyday social contexts. Other settings include virtual environments (8 studies), which have gained significance, particularly in light of the COVID-19 pandemic, as more people have turned to online platforms for social interaction. Additionally, some studies were conducted in home-based settings, as well as in health care units and institutional settings such as nursing homes. The studies also varied in terms of sample sizes, ranging from small samples (7 participants) to large-scale studies involving over 35,000 participants.

The main sources of evidence on loneliness are diverse and include a range of study designs. The predominant method used in the dataset is a cross-sectional study, which explore the relationships between loneliness and various demographic or psychological factors. These studies, including those by Canjuga, Železnik, Neuberg, et al. (2018) and Liu (2022), provide valuable insights into how loneliness is associated with factors such as gender, age, health status, and social context. Cross-sectional studies are essential for identifying patterns and correlations that may inform interventions and further research. In addition to quantitative studies, qualitative research has also been crucial in exploring the subjective experiences of loneliness. For example, Aedo-Neira (2022) used qualitative methods to capture in-depth narratives from individuals experiencing loneliness, providing a valuable context for understanding how loneliness is felt and expressed. Scoping reviews, such as Tragantzopoulou and Giannouli (2021), are instrumental in synthesizing existing research, mapping the landscape of loneliness studies, and identifying research gaps.

Key concepts related to loneliness

Multiple studies distinguish between loneliness and social isolation. Specifically, loneliness, the emotional feeling of being disconnected or lacking meaningful social relationships, and social isolation, the objective measure of the absence of social interactions or connections, have been emphasized in various studies [35, 42, 44, 45], including the scoping review by Tragantzopoulou and Giannouli (2021).

Mental health and self-esteem are frequently examined in relation to loneliness, with studies such as Canjuga, Železnik, Bozicevic, et al. (2018) investigating how loneliness impacts mental well-being, including self-esteem. Scales such as the Rosenberg Self-Esteem Scale are commonly used to assess these variables. Research consistently shows that loneliness is associated with poorer mental health, including depression, anxiety, and lower self-esteem [41, 56,57,58, 67]. These effects are particularly evident in older adults, who may experience compounded psychological distress due to other life changes, such as retirement, health decline, or bereavement. The impact of loneliness on self-esteem is particularly noteworthy, as it often leads to a sense of worthlessness and further exacerbates feelings of isolation.

Figure 2 (social and relational dynamics) illustrates the key factors related to loneliness and social isolation, summarizing how individual characteristics, environmental and socioeconomic factors, and social and relational dynamics interact.

The emotional and social dimensions of loneliness are also key areas of focus. Studies distinguish between emotional loneliness, which refers to the absence of close, intimate relationships, and social loneliness, which is related to the lack of a broader social network [35, 50, 54, 65, 70]. These dimensions are often interlinked with emotions such as sadness, anxiety, and frustration. For example, Aedo-Neira (2022) highlighted the importance of these variables in understanding the subjective experiences of loneliness, especially in vulnerable groups such as elderly individuals. The emotional distress caused by loneliness can manifest in various ways, including heightened anxiety, depressive symptoms, and a sense of emotional emptiness [41, 56, 58, 66, 67, 69]. Such emotional outcomes are critical for qualitative studies that aim to capture the lived experiences of individuals who are lonely, as these emotional experiences are difficult to quantify but vital for understanding the personal impact of loneliness [65].

Personality traits and environmental factors are other crucial variables influencing loneliness and are represented as an individual characteristic in Fig. 2. Research by Liu (2022) and others underscores the role of personality in loneliness, finding that introverted individuals or those with a tendency towards social withdrawal are more likely to experience loneliness [32, 47, 49, 62]. Similarly, environmental factors such as living in rural versus urban areas or in residential versus community settings can affect the extent to which individuals feel socially connected [32, 47, 49, 62, 71]. For example, rural areas may lack the social infrastructure that facilitates regular social interactions, increasing the likelihood of social isolation. On the other hand, people living in urban environments may be surrounded by large numbers of people but still experience social loneliness if they lack close personal connections or feel disconnected from their social surroundings. The type of residential setting also plays a role, as those in institutional or health care settings may feel more isolated than those in community environments due to the lack of autonomy and personal relationships (environmental and socioeconomic factors. Figure 2).

Fig. 2

Key factors related to loneliness and social isolation Note: The colors indicate the level of frequency of articles. Green: Low frequency [1,2,3], Purple: Moderate frequency [4,5,6,7] and Red: High frequency [8,9,10,11]

Main consequences of social isolation and loneliness

The literature reviewed reveals a strong association between loneliness and social isolation and a range of physical health issues. Many studies link these conditions to an increased risk of cardiovascular disease, frailty, and a greater likelihood of developing chronic illnesses [23, 40, 46, 48, 57, 59, 72]. These physical health concerns are particularly prevalent in populations with limited social connections or those who experience higher levels of isolation. For example, as shown in Table 2, various studies highlight how the negative health impacts of loneliness and social isolation manifest in diverse forms, including cardiovascular issues and frailty, primarily among older adults and individuals in isolated settings. These conditions are exacerbated by prolonged isolation, underscoring the importance of social connections in maintaining physical health.

In addition to physical health, the mental health consequences of loneliness and social isolation are frequently reported in the studies included in this review. These include increased rates of depression, anxiety, sleep disorders, and cognitive decline [41, 57, 60, 69, 71, 72]. The data summarized in Table 3 suggest that loneliness often leads to a deterioration in mental well-being, particularly among older adults. Chronic loneliness can serve as a significant stressor, accelerating cognitive decline and increasing the likelihood of developing mental health disorders such as depression and anxiety. Studies consistently emphasize that the effects of loneliness are particularly pronounced in older populations, where social isolation exacerbates emotional distress and can contribute to the onset of conditions such as dementia.

The impact of loneliness extends beyond mental health, affecting overall well-being. Social isolation often leads to reduced social interactions, which subsequently lowers quality of life and diminishes social support [24, 32, 36, 41, 48, 58]. As shown in Table 3, the effects of isolation can lead to significant reductions in quality of life, where individuals experience greater loneliness and a sense of disconnection from others. This lack of social engagement further contributes to emotional and mental health issues, reinforcing the vicious cycle of loneliness. Without sufficient social interactions, individuals can experience increased feelings of helplessness and emotional distress, diminishing their overall quality of life.

An important aspect of this review was the exploration of gender differences in the effects of loneliness and social isolation. Some studies indicate that women are particularly vulnerable to the psychological effects of loneliness, reporting higher levels of depression and anxiety related to isolation compared to men [32, 35, 67, 69, 72]. This is consistent with the findings in Table 2, which indicate that women are more likely to report higher levels of mental distress associated with loneliness, especially in later life. This heightened vulnerability may be attributed to gendered social expectations, caregiving roles, and the greater emotional expressiveness often expected of women. On the other hand, men may experience different social impacts, such as the effects of retirement on loneliness [35, 40, 54, 68, 72]. As noted in Table 2, men often face challenges related to the loss of work-related social networks and changes in their roles postretirement, which can contribute to feelings of isolation.

Overall, the main consequences of social isolation and loneliness identified in the literature are far-reaching and affect both physical and mental health. As illustrated in Table 3, loneliness is linked to a range of health issues, including cardiovascular problems and frailty, as well as emotional health challenges such as depression, anxiety, and cognitive decline. The cyclical nature of loneliness reinforces its negative impact on health, leading to reduced social interactions and further deterioration in mental well-being. Additionally, gender differences must be considered, as women and men experience and respond to loneliness in different ways.

Furthermore, this scoping review also identified what is being studied in documents published in the “grey literature”. In general, these documents confirmed the findings established in scientific documents collected through the databases used in this investigation. These sources provided several key insights into the issue of loneliness and social isolation, complementing peer-reviewed studies.

First, many studies have emphasized the negative impact of loneliness on the mental, social, and physical health of older adults, with particular attention given to its effects on psychiatric patients [74]. These studies reinforced the finding that isolation exacerbates physical and mental health problems, especially for vulnerable groups.

Additionally, several grey literature documents noted that interventions to combat loneliness and isolation could be effective, particularly when tailored to social relationships, physical health, and mental well-being. These interventions are essential for improving the quality of life of those affected [75]. Another notable finding was the economic implications of addressing loneliness. Although interventions may have upfront costs, they also represent an opportunity for new business ventures focused [76] on providing services for those suffering from loneliness, such as social programs or elder care services.

Finally, some grey literature sources highlighted the need for further research to consolidate findings and improve interventions [77].

Table 3 Consequences of loneliness and social isolation

Discussion

This research successfully addressed its key objectives by identifying and mapping the principal factors related to loneliness, examining the main sources of evidence and research gaps, documenting the consequences of loneliness and social isolation, and capturing the diversity of study designs and methodologies. Additionally, it assessed the feasibility of a full systematic review and provided valuable insights for future research by highlighting common variables and methodological approaches in the field.

Loneliness, as evidence suggests, is characterized as the subjective experience of social disconnection and is increasingly recognized as a significant public health concern, particularly among older adults. It is a complex and multifaceted phenomenon influenced by individual characteristics, social dynamics, and environmental contexts. Understanding the details of loneliness and its consequences in this population is essential for designing effective interventions. In contrast, social isolation is an objective condition characterized by a lack of social interaction, contact, and relationships. Understanding this difference is critical because individuals may experience loneliness despite having social connections or, conversely, may not feel lonely even when socially isolated. The distinction between these two concepts allows for a more comprehensive understanding of how loneliness affects individuals differently depending on their social and emotional experiences.

This review synthesizes current evidence on the determinants, impacts, and potential strategies to address loneliness in ageing populations, emphasizing the need for an integrated and tailored approach.

Individual characteristics and loneliness

The experience of loneliness is deeply rooted in individual characteristics, including personality traits, mental health, and self-care abilities [24]. Research consistently highlights personality as a significant determinant of loneliness. Traits such as introversion, social withdrawal, and low emotional resilience are associated with increased prevalence of loneliness, particularly in men and women aged 60–79 years [78]. These traits often limit individuals’ ability to form or maintain meaningful social relationships, intensifying feelings of disconnection.

Mental health plays a central role in exacerbating loneliness. Older adults frequently encounter compounded challenges such as declining health, bereavement, and the transition to retirement, which collectively increase psychological distress [28, 79]. This distress manifests as decreased self-esteem, heightened anxiety, and depression, creating a cyclical relationship in which loneliness exacerbates mental health issues in turn. These findings underscore the necessity of interventions that address these interconnected psychological dimensions, emphasizing the need for tools that enhance resilience and coping mechanisms in vulnerable populations.

Self-care abilities, including physical health and lifestyle factors, also intersect with loneliness. Velarde-Mayol et al. (2016) concluded that key lifestyle factors, such as physical activity, social engagement, sleep quality, and diet, were significantly associated with levels of loneliness [80]. Specifically, individuals who led an active lifestyle, maintained regular social interactions, and had healthy sleep and dietary habits reported lower levels of loneliness.

Frailty and chronic illness not only limit mobility but also reduce opportunities for social engagement, further isolating individuals [23]. These observations suggest that fostering physical health and autonomy can have a protective effect against loneliness, particularly when integrated into holistic health promotion strategies. The literature shows the importance of public health policies and community programs aimed at fostering social connections and promoting healthier lifestyle choices to mitigate loneliness across different demographics in urban areas.

Relational and social dimensions of loneliness

Loneliness is often categorized into emotional and social dimensions [25]. Emotional loneliness arises from the absence of intimate, close relationships, whereas social loneliness reflects a lack of broader social networks. Both forms of loneliness are prevalent among older individuals with severe emotional impacts, with studies exposing their interdependent nature and severe emotional impact [22]. Emotional loneliness, for example, can persist even in the presence of social interactions if those interactions lack depth or fail to meet emotional needs. Conversely, social loneliness often stems from situational factors, such as the loss of a spouse or diminished community engagement.

The COVID-19 pandemic has further highlighted the complexities of these relational dimensions [81]. The increased reliance on virtual environments for social interaction has demonstrated both the potential and the limitations of digital tools in mitigating loneliness. Although online platforms have alleviated some aspects of social isolation, they have proven less effective in addressing emotional loneliness, highlighting the need for strategies that foster meaningful and emotionally satisfying connections.

Environmental and socioeconomic influences in community-dwelling older adults

Environmental and socioeconomic factors play essential roles in shaping the experience of loneliness among community-dwelling older adults. Geographic location significantly impacts social connectivity. Rural residents often face heightened risks of loneliness due to limited social infrastructure and fewer opportunities for interaction, whereas urban dwellers may experience social loneliness stemming from feelings of anonymity and disconnection in densely populated environments [35].

Residential settings further influence loneliness dynamics. Older adults in institutional environments, such as nursing homes, are particularly vulnerable due to restricted autonomy and limited opportunities for relationship building. However, those living in community-based settings generally report lower loneliness levels, likely due to greater access to social engagement opportunities. Community-dwelling older adults face unique challenges, with an estimated 20–30% experiencing significant social isolation [82]. Barriers such as limited access to transportation, inadequate digital literacy, and reduced physical mobility exacerbate their isolation [83]. Additionally, the geographic dispersion of families and the loss of close relationships compound these challenges, highlighting the need for accessible community services and innovative digital solutions to enhance connectivity. The concept of social networks is highlighted as an important factor influencing the mental health and emotional well-being of elderly people [84, 85].

Evidence shows how socioeconomic factors, such as income inequality, access to resources, and digital literacy, compound these challenges, emphasizing the importance of policy interventions aimed at reducing disparities and fostering inclusive social environments.

Consequences of loneliness

Most studies have shown that the consequences of loneliness extend across physical, mental, and social domains. Physically, loneliness is linked to increased risks of cardiovascular disease, cognitive decline, and frailty through mechanisms such as chronic stress, poor sleep quality, and immune dysregulation [86]. Social isolation, a related but distinct phenomenon, further exacerbates these risks by limiting opportunities for physical activity and social interaction [87]. These findings highlight the critical role of physical and social engagement in mitigating the health impacts of loneliness.

Mentally, loneliness significantly affects psychological well-being, contributing to higher rates of depression, anxiety, and cognitive decline. Neurobiological research suggests that loneliness enhances vigilance to social threats and diminishes the enjoyment of social interactions, as evidenced by structural changes in brain areas associated with social perception [49]. These insights underscore the importance of addressing both the emotional and the cognitive dimensions of loneliness in intervention strategies [36].

Socially, loneliness limits community participation and reduces the size and quality of social networks. This social exclusion perpetuates a cycle of isolation, making it increasingly difficult for individuals to reintegrate into social contexts [28]. Efforts to combat this cycle must focus on reactivating social networks and fostering inclusive community engagement.

Gender perspective and loneliness

Gender significantly influences how loneliness is experienced and mitigated among older adults. Research has shown that gender can influence how social determinants affect quality of life [88]. Societal shifts, such as the increased labour force participation of women, have altered traditional family structures and intergenerational support systems, contributing to a greater prevalence of loneliness in older individuals [89]. Men and women also differ in how they benefit from social connections. For example, men derive greater quality-of-life improvements from social networks, whereas women benefit more from active social participation [88]. These differences underscore the importance of gender-sensitive approaches to designing interventions, such as strengthening social networks for men and promoting engagement activities for women.

Research gaps and future directions

Despite a growing body of evidence, several research gaps persist. Many studies rely on cross-sectional or qualitative designs, limiting insights into the longitudinal dynamics of loneliness and its causal effects on health. The small number of studies per intervention limits conclusions on sources of heterogeneity. The inconsistent use of standardized measures further complicates comparisons across studies, suggesting a need for harmonized methodologies. Additionally, although digital interventions hold promise, their role in addressing emotional loneliness remains underexplored. Intersectional analyses that consider the interplay of gender, age, socioeconomic status, and cultural factors are also lacking, despite their importance for developing equitable interventions.

These findings underscore the need for comprehensive approaches to address loneliness, considering both its physical and psychological dimensions and its gendered impacts.

This broad range of study designs and settings reflects the multifactorial nature of loneliness and the need for diverse research approaches to fully understand its causes, consequences, and potential solutions.

The evidence is consistent with a gap in the current literature, suggesting that more rigorous studies are needed to understand the long-term impacts of loneliness and the effectiveness of interventions [77].

In conclusion, loneliness in older adults is a multifaceted issue with profound implications for physical, mental, and social well-being. This article provides a comprehensive review of the literature regarding this increasing number of phenomena. Addressing this challenge requires an integrative approach that considers individual, relational, and environmental determinants. Tailored, gender-sensitive interventions, alongside policy initiatives that reduce socioeconomic disparities and enhance social support systems, are critical. Future research should prioritize longitudinal designs, standardized measures, and intersectional frameworks to advance understanding and inform effective strategies. As the global population continues to age, addressing loneliness and social isolation must remain a priority for public health, policy, and research communities.

Strengths and limitations of this scoping review

The primary strength of this review lies in its specific and contemporary focus, analysing loneliness and social isolation among community-dwelling older adults—a population less studied than institutionalized groups. By including research conducted in the past decade, this review offers an updated perspective on a growing issue in ageing populations. Furthermore, the methodology employed, which is based on the PRISMA-ScR guidelines and Arksey and O’Malley’s framework, ensures a systematic and rigorous approach. The inclusion of diverse sources, encompassing both the scientific and grey literature, alongside consideration of broad geographical contexts and varied methods (quantitative, qualitative, and mixed), enriches the understanding of this phenomenon. Additionally, this review identifies key research gaps, such as the need for longitudinal analyses and the exploration of intersectional factors, including gender, socioeconomic status, and culture.

However, this review also has notable limitations. Restricting the analysis to studies published in English and Spanish may have excluded relevant research in other languages, limiting the representativeness of findings in specific regions. Moreover, focusing exclusively on the past decade may overlook historical trends or foundational studies that provide a broader context. The heterogeneity of the included studies, particularly in terms of definitions, measurement tools, and methodological approaches, complicates the comparison and synthesis of results. Finally, the exclusion of studies without full-text availability and the limited analysis of intervention effectiveness highlight areas that warrant further exploration in future research.