Loneliness is a growing concern in the United Kingdom, with its prevalence increasing year over year [1]. The Campaign to End Loneliness published data showing that 49.63% of UK adults report feeling lonely often or sometimes [2]. This prevalence is seen internationally, with 40% of older adults in the United States reporting feeling lonely [3] and 37.9% for Chinese adults aged older than 50 years [4]. Understanding this concern at an individual level is pertinent as loneliness demonstrates bidirectional relationships with other mental health concerns [5], whereby loneliness both increases vulnerability to mental health difficulties and emerges as a consequence of them.

While numerous validated scales exist to quantify loneliness experiences across populations (eg, the University of California, Los Angeles [UCLA] Loneliness Scale and the De Jong Gierveld [DJG] Loneliness Scale) [6,7], there remains limited research examining how loneliness manifests within therapeutic practice from practitioners’ perspectives, particularly in digital mental health contexts.

Given the relationship between loneliness and co-occurring mental health conditions [8,9] and the interpersonal stigma that may affect therapeutic disclosure [10,11], understanding how experienced practitioners identify and interpret loneliness presentations is crucial for informing therapeutic practice and intervention approaches.

With the advent of digital mental health interventions, those in need have more ready access to cost-effective and context-appropriate therapy. Online interventions can be broad or targeted, with numerous services for anxiety, depression, and suicide prevention [12-14]. There are also broader interventions such as internet-based cognitive behavioral therapy [15] and text-based talking therapies [16].

As digital mental health platforms become increasingly prominent points of therapeutic contact [12], questions arise about how loneliness manifests and is communicated within these environments. Practitioners working in these contexts may observe distinct patterns in how clients express concerns through text-based interactions, or alternatively, expression may remain consistent across therapeutic modalities. Understanding practitioners’ perspectives from these digital environments provides an opportunity to examine loneliness disclosure patterns in contemporary therapeutic practice and explore how interpersonal stigma operates within online therapeutic relationships.

This study focuses on practitioner insights through a thematic analysis (TA) of experienced practitioners in digital therapeutic practice. This study’s aims were the following: (1) understand how practitioners identify loneliness concerns, (2) identify how loneliness is elicited in digital mental health interventions, and (3) identify co-occurring themes (such as grief, shame, and social disconnection) that signal loneliness within digital therapeutic environments.

These aims enable the exploration of the following question: How do digital mental health practitioners provide insight into loneliness in digital therapeutic contexts? Furthermore, this study seeks to develop a comprehensive understanding of how loneliness is directly and indirectly expressed by clients in digital mental health settings through practitioner interviews.

The growth of digital mental health interventions has created a substantial cohort of practitioners with experience in identifying and responding to loneliness concerns across diverse client populations. Practitioners occupy a unique observational position in loneliness research. While individual clients may experience loneliness, practitioners encounter multiple cases over time, enabling the identification of patterns in disclosure, the recognition of co-occurring themes, and the observation of how loneliness manifests in therapeutic contexts. This accumulated clinical expertise represents a valuable but underexplored data source for understanding how loneliness is expressed, experienced, and addressed in contemporary digital therapeutic practice.

While there are quantitative elucidations into the co-occurring factors of loneliness [17,18], qualitative evidence can offer nuanced experiences that a loneliness survey or measure cannot achieve due to an individual’s inability to describe their lived experience.

There have been several qualitative studies examining the experience of loneliness; however, they are primarily from the lonely individual’s perspective. Such studies are often stratified by a specific demographic characteristic [19]. Although there are nuances across these demographics, similar trends have emerged, such as the importance of connectedness to the experience of loneliness [20]. Studies have shown a U-shaped distribution across age, indicating that younger and older individuals experience loneliness more frequently than those in middle age [19,21,22].

Qualitative research has identified consistent experiences that can be used to identify the core characteristics of loneliness. Martin et al [23] interviewed 33 adolescents stratified by socioeconomic area, finding that young people identified two core elements defining their loneliness experience: (1) connectedness with friends and (2) perceptions of “aloneness.” Fardghassemi and Joffe [24] used a free association technique and TA with 48 young adults (aged 18‐24 years) from the four most deprived boroughs of London, identifying the following five key themes explaining the subjective causes of loneliness: (1) The Feeling of Being Disconnected, arising from feeling one does not matter, is not understood, or is unable to express oneself; (2) Contemporary Culture, relating to social media and materialism; (3) Pressure, associated with finding work or friends; (4) Social Comparison; and (5) Transitions Between Life Stages, including the breakdown of relationships and transitions in education or employment. These identified themes offer a subjective overview of loneliness, which warrants further specific contextual analysis.

Loneliness is highly contextual and often related to a number of co-occurring facets of a person’s life. For example, Verity et al [25] evaluated how young people conceptualize loneliness across age ranges through qualitative interviews with 24 young people aged 8‐14 years. They found that young people conceptualize loneliness differently in different contexts, such as the experience of loneliness at school compared with loneliness at home. Verity et al [25] also reinforced the idea that loneliness cannot be attributed to a single cause but varies across the sample, such as change or social exclusion from peer groups, causing increased loneliness. These identified experiences offer an overview of the subjective experience of loneliness but do not address how these experiences are communicated or identified within therapeutic practice.

Themes of connectedness and social comparison are present across different age groups and study contexts. Both studies by Fardghassemi and Joffe [24] and Martin et al [23] highlight that loneliness fundamentally stems from a perceived lack of meaningful connection rather than just being alone, suggesting that regardless of specific demographic characteristics or qualitative approaches, the loneliness experience centers on unmet needs for meaningful social connections. While these contextual concerns do offer some insight into loneliness, stigma serves as a significant overarching experience of an individual’s lived experience, which directly exacerbates feelings of loneliness.

Stigma is of particular note as it leads to challenges in both social and therapeutic environments, where an individual may not be as open to discussing a concern due to the stigmatized nature of either the antagonist of loneliness or loneliness itself. Barreto et al [10] analyzed loneliness and stigma across several determinants, finding that the stigma of loneliness significantly affects disclosure patterns, with one third of UK respondents reporting that they would be embarrassed to admit feeling lonely, and quantitative loneliness measures producing higher scores when avoiding direct loneliness terminology. Barreto et al [10] demonstrated that stigma drives concealment behaviors, with women more likely to report shame when experiencing loneliness, while men perceived greater community stigma around loneliness, providing support for why clients might avoid direct loneliness expression in therapeutic settings. There is a link between experiences of shame and loneliness [26,27]. The way in which mental health concerns are discussed in the media also contributes to their general stigmatization [28] as they are seen to be negative experiences. People with mental illness are presented in the media as “peculiar,” “different,” and “dangerous” [29], providing a narrative which perpetuates sensationalized and stigmatizing characterizations [30].

Crucially, it has been established that those who experience loneliness feel shame because they are lonely; Dahlberg [31] evaluated interviews with participants aged between 11 and 82 years, who described the experience of loneliness as “shameful” and “ugly.” Loneliness can perpetuate from feelings of shame (rather than only causing shameful feelings) for those who have been othered in some way [11], such as those who experience rejection and neglect from peers, who may feel particularly stigmatized [10,27,32]. Madsen et al [33] conducted 15 semistructured individual interviews with adolescents aged 14‐15 years who were immigrants, descendants, or had a Danish majority background, finding that loneliness was often described as a challenging feeling that varied in intensity and duration. Crucially, Madsen et al [33] characterized loneliness as an “invisible social stigma,” in which loneliness itself is a stigmatized experience. Stigma as a driving force of loneliness may therefore shape how individuals disclose loneliness within therapeutic contexts, representing a gap in the broader literature that practitioner perspectives are uniquely positioned to address.

Mental health is a stigmatized experience that often co-occurs with loneliness [34-36], and understanding the relationship between this specific preexisting stigma and loneliness is particularly critical.

The idea of being “othered” is a factor in the experience of mental health concerns; in turn, those who experience significant or severe mental health episodes, such as psychosis, are often lonely due to this isolating experience and the stigma around these concerns [9,36,37]. There is an established relationship between loneliness and mental health concerns. Birken et al [38] interviewed people who had self-reported mental health concerns to establish connections between loneliness and mental health, identifying contributory factors to continuing loneliness and approaches for reducing loneliness.

While there are overlaps between loneliness and depression, understanding how practitioners differentiate these experiences in clinical practice requires observing the ways clients express loneliness within therapeutic environments. While individual lived experience remains crucial for understanding loneliness, practitioners’ perspectives offer a unique viewpoint, as their exposure to multiple loneliness presentations enables them to identify patterns that may not be apparent from individual accounts alone.

Without practice-based insight from practitioners, the way in which loneliness is expressed and the experiences therein remain opaque. However, few qualitative interview studies of practitioners have been undertaken.

Stefanidou et al [39] interviewed 20 mental health practitioners who focus on first-episode psychosis in the United Kingdom; they reported that the majority of service users with early psychosis experience feelings of loneliness. They often encountered socially isolated and disconnected clients, believing them to be lonely, but service users rarely discussed loneliness explicitly in clinical interactions.

Dobarrio-Sanz et al [40] interviewed 26 health care professionals about their perceptions of loneliness in older adults, identifying that loneliness is highly contextual and should be taken more seriously as a public health concern. Verity et al [41] analyzed online counseling conversations between Childline counselors and adolescents, finding that issues with trust and self-worth acted as significant barriers to help-seeking, consistent with the broader pattern of stigma-driven concealment of loneliness concerns.

These insights reinforce the consistent pattern across age groups and clinical contexts that loneliness fundamentally centers on peer relationship quality and social environmental pressures, regardless of age group or other demographic characteristics.

While not specifically mental health practitioners, Jovicic and McPherson [42] interviewed general practitioners (GPs), finding that those experiencing loneliness visit their GP more frequently than those who are not, which has the potential to put a strain on GP and health support waiting lists while also increasing costs. They also determined that loneliness co-occurs with physical and mental health conditions while affecting cognition and lifestyle.

There are consistent themes around connectedness and stigma that emerge from studies with both individuals and practitioners. Practitioner insights are rarely examined; however, when they are, they reveal ways in which individuals experience loneliness [39,40,43]. For example, there is specific language used by those who experience loneliness and disclose it to practitioners. Understanding the language used to disclose loneliness can provide practitioners with context for identifying when a client is expressing loneliness and offer some understanding of the nuances of the experience.

This study addresses the gap in limited practitioner-based conceptualization, in which practitioners describe their experiences of engaging with clients in several contexts and provide much-needed elucidation and evidence regarding loneliness in therapeutic practice. Practitioners can also observe longitudinal patterns and changes across treatment periods, providing contextualization of challenges that individual client interviews might overlook. This opportunity to recognize patterns across cases represents an opportunity to enhance our understanding of loneliness, which is unavailable through studies of single instances of loneliness.

While this preceding body of work (summarized in Table 1) demonstrates the co-occurring themes based on practitioner expertise, there remains very limited qualitative research focusing specifically on practitioners within digital mental health interventions. This is a notable gap given the growing uptake of online mental health support, and the unique ways in which loneliness might be expressed and addressed in digital contexts. This study addresses this gap by examining how digital mental health practitioners perceive and respond to loneliness in their practice.

TA of practitioner interviews was selected as the methodological approach, as it enables a granular view of loneliness across digital practice. Therefore, practitioners who practice digitally were recruited to answer a series of questions about their clients’ experience of loneliness. The scope of this paper is focused on practitioners’ experiences and perceptions of loneliness among their service users.

Nine practitioners participated in this study (see Table 2). Of these, 6 identified as female and 2 as male; 1 did not report gender. Participants ranged from 37 to 71 years, with 2 participants not reporting their age. All participants who reported ethnicity identified as White British, with 2 participants not reporting ethnicity. Participants were distributed across three digital mental health platforms: Kooth (n=3), Togetherall (n=2), and the Association for Counselling and Therapy Online (ACTO; n=4). The specific professional roles spanned grief therapy, emotional well-being practice, psychotherapy, mental health nursing, and dialectical behavior therapy, reflecting a range of clinical specialties and therapeutic approaches within digital mental health practice.

The ACTO is a UK professional membership organization that sets ethical and competency standards for practitioners delivering therapy remotely. ACTO maintains a directory of accredited online therapists and provides specialist training guidance functioning as a regulatory reference point and a professional support network for practitioners working in digital contexts.

Semistructured interviews were conducted using questions based on established literature to gain specific insights into the lived experience of loneliness and the language often used when disclosing concerns about loneliness. The interview schedule included the following questions:

TA, an iterative method was used to evaluate qualitative data [44]. Through TA, interview content was classified into broad themes, primarily driven by predefined interview questions. The semistructured nature of the interviews allowed the interviewer and practitioners to discuss tangential yet conceptually related themes that emerged during the interview. Themes were refined as the interviews were conducted, enabling the researcher to identify the point at which saturation of relevant opinions appeared to occur. Analysis used an inductive approach, allowing themes to emerge from participants’ accounts rather than fitting data into preexisting theoretical frameworks.

Analytic decisions during theme development were guided by the frequency and consistency of codes across the interview sample. Core themes were established as they recurred across the interviews, with codes appearing in only one or two interviews either absorbed into broader themes where conceptual overlap existed or excluded where codes represented contextually specific rather than generalizable themes. Coding and initial theme development were conducted by the lead researcher, who was also the interviewer, with themes subsequently reviewed and discussed with the wider research team to support analytical rigor.

Data saturation was approached pragmatically, recognizing that complete theoretical saturation is rarely achievable in qualitative research [45]. After nine interviews, the core thematic structure had been established, with no new primary themes emerging.

TA was performed using the following 6-phase approach outlined by Braun and Clarke [46]:

The lead researcher approached this study from a multidisciplinary background in computing and psychotherapy research. To develop contextual familiarity with therapeutic practice, engagement with counseling literature and practice was undertaken before data collection. Analysis was conducted by a single coder, and the themes were evaluated by the wider research team. It is acknowledged that the interpretive process was informed by a prior theoretical assumption consistent with Hawkley and Cacioppo’s framework [20], namely, that loneliness reflects a discrepancy between desired and actual social connection. This assumption is made transparent here as it may have shaped the salience of certain themes during coding.

Ethical approval for this study was granted by the University of Nottingham Business School (application ID 202324037). The practitioner participants provided written informed consent when participating in the conducted interviews. Participants’ data has been anonymized in line with the University of Nottingham research ethics guidelines.

TA of the semistructured interview transcripts revealed several interconnected themes related to the experience of loneliness. Based on transcript coding, the following four core themes were identified (see Table 3): (1) Conceptualizing Loneliness, (2) The Contextual Factors and Causes of Loneliness, (3) the Expressions and Language of Loneliness, and (4) The Co-occurrence of Loneliness and Mental Health Concerns. These themes directly address the research aims to understand how practitioners identify loneliness, its prevalence and manifestations in digital mental health interventions, and the expressions and co-occurring concerns that signal loneliness.

Across all 4 themes, practitioners described loneliness as a complex experience shaped by internal feelings, relational contexts, and broader social structures. The findings show that loneliness is rarely disclosed directly, often masked by proxy language or overshadowed by co-occurring mental health concerns. Furthermore, loneliness is caused by several factors, from life transitions and stigma to the symptoms of severe mental health conditions. This complexity means that loneliness cannot be reduced to the absence of social contact, but must be understood in terms of the quality, meaning, and accessibility of relationships. These observations highlight the importance of practitioner skill in recognizing subtle expressions of loneliness and addressing its psychological and social drivers. The discussion that follows situates these findings within the wider literature, examining how they align with, challenge, and extend existing understandings of loneliness in digital mental health contexts.

This study has further presented the significance of stigma as a facet of loneliness. Stigma operates at two levels within the experience of loneliness: (1) stigma functions as a contextual instigator that increases the propensity for loneliness (through social exclusion and identity-related isolation) and (2) the intrinsic stigma and shame associated with being lonely. This perspective on stigma expands upon previous research identifying the interaction between stigma and loneliness, particularly as practitioners were able to identify concerns through this relationship, suggesting that this can serve as a proxy indicator for identifying loneliness triggers in therapeutic practice.

Practitioner insights about disconnection and a lack of quality social connections aligned with established literature [23,24] and the items in prevailing loneliness measures (particularly the UCLA and DJG Loneliness Scales). This finding resonates with specific concepts from these scales and their conceptualizations of loneliness, in which limited meaningful connections are present for the individual experiencing loneliness (as summarized in Table 4). For example, items 6 and 9 of the UCLA Loneliness Scale (“I have a lot in common with the people around me” and “My interests and ideas are not shared by those around me”) mirror the observations from practitioners that people may feel a lack of connection with others due to surface-level interests. This extends to indirect expression of loneliness; for example, “I don’t feel like they are my actual friends” mirrors item 12 in the UCLA Loneliness Scale: “My social relationships are superficial.”

The DJG scale items further reflect practitioner observations about client language patterns. The item “I experience a general sense of emptiness” aligns with practitioners’ reports that clients frequently use metaphorical expressions such as “hollow,” “empty,” and “desolate” to describe their loneliness without using direct terminology. Similarly, the DJG item “I miss having people around me” corresponds to the indirect expressions practitioners identified, such as “I don't feel like I have anyone to talk to.” The DJG item “I often feel rejected” particularly aligns with practitioners’ observations about clients experiencing stigma-based social exclusion, whether due to cultural identity, sexuality, or other marginalizing factors. It should be noted that the items included in these 2 scales were developed in the 1960s and 1970s, suggesting that how individuals describe feelings of loneliness has not changed over time.

Practitioners’ conceptualizations of loneliness align with established theoretical frameworks and measurement approaches. Specifically, practitioner perspectives connect directly with the definition of loneliness as the “subjective perception of a discrepancy between the desired and true social relationships in terms of companionship, connectivity, or intimacy.” [20] Together, these parallels across measurement tools underscore that practitioner perspectives reflect the same relational and emotional dimensions captured in validated loneliness scales, while revealing how these experiences are expressed in therapeutic contexts. This warrants further investigation, as it is unclear whether the coalesced conceptualization is due to the practitioners having been trained on the established scales and concepts, which have shaped their perception, or if their understanding is based on their experience of interacting with and supporting lonely people.

This work also builds upon research on the indirect language of loneliness, demonstrating that expressions of loneliness by clients in traditional therapeutic environments align with those in online and digital interventions [41,48].

These findings extend the findings provided by Verity et al [25], wherein young people described a discrete set of emotions to characterize the experience of loneliness, including “sadness,” “anger,” “emptiness,” “feeling unloved,” and “hopeless.” Furthermore, practitioners noted that clients would disclose feeling disconnected or hopeless about their social situation without directly acknowledging the feeling of loneliness. These feelings were identified as indirect expressions, particularly practitioners reporting clients describing themselves as “depressed” rather than lonely, which aligns with the work by Cacioppo et al [49], which identified some overlap in the experience of depression and loneliness. However, this research identifies that this disclosure of depression could be due to the client’s clinical vocabulary rather than their true experience. More specifically, depression is used as a description of how people feel, which may be true for clients, but this is distinctly different from loneliness as a specific feeling related to the lack of social connection as established by Cacioppo et al [49] and Weiss [50].

This analysis provides novel perspectives on the specific ways in which loneliness is elicited by different age groups, identifying a previously undocumented developmental progression in loneliness language. The language used by older people is often more direct and “traditional” compared to the clinical terminology that has become embedded in young people’s emotional vocabulary, suggesting that mental health literacy may incongruously create new barriers to authentic emotional expression.

The insights reveal how loneliness impacts individuals’ approaches to therapeutic disclosure in digital intervention environments. These findings extend existing loneliness measurement theory by highlighting the value of loneliness measurement tools that do not use direct loneliness questions, such as “How often do you feel lonely?” Rather, these findings validate the effectiveness of indirect assessment approaches while providing insight into their efficacy, due to interpersonal stigma preventing direct therapeutic disclosure.

The contextual triggers of loneliness identified by practitioners were numerous, particularly affecting those who have minority status within a dominant culture and face challenges in conforming to social norms because of their cultural background. This type of stigma can lead to feeling disconnected from the broader culture that surrounds them. Other specific examples include lesbian, gay, bisexual, transgender, and queer or questioning plus or neurodiverse populations [10,31], whose experiences are less understood or who are actively othered by their community.

The significant impact of life transitions identified by practitioners aligns with Lim et al’s [8] assessment of loneliness triggers, where life transitions precede and instigate loneliness. Practitioners identified triggers such as moving away from home [24], divorce (the breakdown of a relationship) [51], or the death of a spouse (with the associated grief and loss) [24].

The practitioners identified reductions in social spaces and government resources combined with an increased cost of living as contributing to loneliness through limitations in social activities due to cost and through the stigma of having to engage in social support; this aligns with and expands on the findings of Cheetham et al [52]. These factors build upon previous research identifying the contextual nature of loneliness while also providing evidence that these elements are consistent in online environments.

While the contextual drivers remain consistent among practitioners in traditional face-to-face interventions and those who practice online, novel insight has been gleaned into the way in which clients, specifically younger clients, express loneliness. Furthermore, regardless of the environment, loneliness is still expressed indirectly through metaphors and similes to minimize the perceived stigma of loneliness.

Recruitment challenges within the specialized population of digital mental health practitioners limited the sample size to 9 participants. The sample was mostly female and entirely White British (where reported), potentially limiting the generalizability of findings across diverse practitioner and client populations. However, the achieved sample demonstrated strong conceptual diversity across practitioner roles and platform types, supporting the credibility of identified themes.

Following recommendations for pragmatic saturation assessment [53], saturation was evaluated based on the sufficiency of data to address research objectives. The central patterns of loneliness expression, contextual causes, and practitioner recognition had reached sufficient depth for meaningful analysis, though additional participants might have provided further nuance.

While this study identified how loneliness is expressed indirectly in therapeutic contexts, questions remain about how digital interventions can effectively address loneliness given these indirect disclosure patterns. The practitioners’ perspectives suggest that understanding service users’ underlying needs may be crucial for developing effective interventions. This provides the foundation for examining how frequently loneliness-related concerns appear among the broader needs of digital mental health service users.

This study provides a theoretical contribution to the literature, collating and synthesizing practitioners' insights. The practitioners identified multiple stigmatizing experiences as contextual drivers of loneliness, highlighting how loneliness emerges not only from individual factors but from broader patterns of social exclusion and marginalization. For therapeutic practice, these insights suggest that practitioners can use awareness of stigmatizing experiences as potential indicators when assessing loneliness risk. The presence of these contextual patterns was consistent across digital therapeutic environments, providing a foundation for developing more targeted interventions that address both the emotional experience of loneliness and its underlying social drivers.