Lonely now or forever? Challenges in studying interactions and interventions: A Letter to the Editor Re: The longitudinal association between loneliness and depressive symptoms in the elderly: a systematic review

I would like to thank Van As et al. for their contribution to the literature on loneliness. Clarifying associations between loneliness and patientoriented outcomes helps to solidify the importance of further research and development of tools to address it. Additionally, I appreciate the authors’ notes on moderators of loneliness, both individual (mobility, cognitive impairment) and systemic (welfare programs, social supports). At the same time, until we have further characterized loneliness, these results and interventions may be limited in their utility. The contextual nature of loneliness, absent from the paper’s discussion, must shape the way we interpret these results and formulate interventions. Community relationships are a crucial part of the context of loneliness. The distinction between social isolation and perceived social isolation sets the stage to explore how specific relationships, as opposed to social connectedness, affect loneliness. Studies show an association between partnered relationships or cohabitation and lower levels of loneliness, but the perceived relationship quality also plays an important role (Hawkley et al., 2008). Studies associate marital strain with increased loneliness (Ermer and Proulx, 2022) and show reduced benefits from other social supports and connectedness in that context (Ermer and Proulx, 2019, 2022). On the other hand, those who are not partneredmay receive more benefit from other support networks such as friends or neighbors (Ermer and Proulx, 2019). Taken together, large community or social support programs may not benefit many with loneliness, especially if their most intimate or centered personal relationships are perceived as deficient in some way. Although we may theorize that marital counseling could serve as an alternative intervention for those in this situation, a search of available databases reveals a paucity of research on the effect of such interventions on loneliness. Peoples’ disposition toward loneliness, including heritability and stability in life, also plays a large role. Loneliness has been associated with neuroticism (Abdellaoui et al., 2019) and insecure attachment styles (Helm et al., 2020) which may persist into late life and affect marital satisfaction and depressive symptoms (Waldinger et al., 2015). A meta-analysis by Mund et al. (2020) demonstrated the stability of loneliness between individuals, mirroring personality characteristics and supporting a possible distinction between dispositional loneliness and episodic loneliness. A later study suggests that dispositional loneliness may predispose people to worse perceptions of intimate relationships (Mund et al., 2022). These studies raise questions of an opposite or bidirectional association between relationship quality and loneliness. Dispositional loneliness also complicates the interpretation of longitudinal studies as assessments of loneliness frequently do not distinguish between it and episodic loneliness. By calling attention to these unanswered questions about the nature of loneliness, we challenge the fundamental assumptions used to interpret longitudinal results and develop interventions targeted toward loneliness. The authors’ discussion regarding policy changes, interventions for community engagement, social supports, technology use, and community-based interventions would likely address some aspects of loneliness. However, if we do not address the individual, human, and relational elements of loneliness, could we miss the mark? Would our interventions address the persistent predisposition some have toward loneliness and provide the quality of relationships and connections that lonely patients need?