Loneliness — What Is It, and Is There an Epidemic? A Conversation with Professor Riedel-Heller (Part 1)

The topic of loneliness has increasingly drawn public attention, not just since the COVID‑19 pandemic. In the past, loneliness was often self‑chosen, for instance by hermits, but today it has become a heavily mediated term. Many people discuss it; initiatives such as the Martinsschmaus Foundation in Jena address “the increasing isolation of seniors and disadvantaged people.”

The scientific community has also engaged with the topic, and research and publications on loneliness have grown substantially in recent years.

So what is “loneliness”? Is it merely a feeling, or also a social and medical issue? We spoke about this with Professor Riedel‑Heller of Leipzig University Hospital. She researches loneliness and played a major role in the September 2024 editorial in the Federal Health Gazette, “Loneliness: A Term for Many Realities”, which we reference in this interview. For this conversation, we agreed to forgo academic titles in our forms of address.

Ms. Riedel‑Heller, from the perspective of the health and social sciences, what exactly is “loneliness”? What is the difference between being lonely and being alone?

There is a clear difference. Loneliness is the gap between the desired degree of being with others and one’s actual situation — for example, wanting more company than one currently has. Being alone, by contrast, simply describes a state at a given moment.

Some people deliberately seek solitude, such as during a stay at a monastery; in that context, it carries a positive meaning. Being alone does not automatically entail feeling lonely. There is a connection, though: people who are alone very often are also lonely more frequently. Still, the two are not equivalent.

The editorial notes: “Science agrees that loneliness, as a subjective perception, must be distinguished from social isolation as an objective condition.” How can non‑specialists tell the difference?

The difference between what one wants and what is the case is a matter of evaluation, and evaluation is subjective. Social isolation, by contrast, concerns the size of one’s network, the number of acquaintances, and the frequency of contact — things that can be counted and measured. Social isolation is therefore more of an objective indicator.

So loneliness is essentially a subjective perception?

Exactly — it reflects how an individual evaluates their own situation. Of course, social isolation and loneliness are linked. People who are socially isolated are more likely to feel lonely, but not invariably.

Does a single, uniform “loneliness” even exist? I recall the 1969 song “Streets of London”: “So, how can you tell me you’re lonely and say for you that the sun don’t shine? Let me take you by the hand and lead you through the streets of London. Show you something to make you change your mind,” roughly: “Don’t complain — others are lonelier than you.” Is each person lonely in a different way?

Yes. Loneliness is a highly subjective construct and thus a subjective judgment. I would say there are nuances. Scientifically, we use established questionnaires and scales to describe the phenomenon, but they can only ever approximate reality.

Reported figures are rising; one paper mentions a fivefold increase since 2019 (pre‑pandemic). It appears that loneliness affects not only seniors and disadvantaged people but spans all age and social groups. Is that accurate?

We can be more nuanced. The prevalence of loneliness follows a U‑shaped curve, peaking in younger ages and then again in older and very old age. We also know loneliness was elevated during the pandemic and, in part, has not yet returned to pre‑pandemic levels. This quickly gives rise to the notion of a loneliness “epidemic.” Several trends could support that view: more single‑person households, increased labor migration, fewer multigenerational homes, more dispersed social networks, high divorce rates, and low birth rates.

Scientifically, though, the question is not straightforward. We would need to measure loneliness in exactly the same way over long periods. Research attention to loneliness is relatively recent. A colleague, Maike Luhmann, examined this question in a meta‑analysis synthesizing many studies. She found no uniform increase. There are specific effects — some among younger people and in certain regions — but no consistent, large upward trend.

We conducted our own research on loneliness during COVID‑19. In the NAKO study, Germany’s largest cohort study, more than 100,000 people were surveyed by mail during the pandemic; 31.5% — nearly one‑third — reported loneliness. Given social‑distancing measures, that is not surprising. Meta‑analyses based on numerous longitudinal studies using consistent instruments before and during the pandemic show that loneliness did increase, but not dramatically; the “epidemic” narrative is viewed skeptically. The topic remains highly relevant nonetheless.

The loneliness of children and adolescents is often a focal point. How do the factors there differ from those in older adults?

My own research centers more on older adults, but it is well established that loneliness among children and adolescents is a concern, and the U‑shaped pattern indicates higher prevalence there. In general, there is no single cause of loneliness; multiple, multilevel factors are at play. Individual factors include personality traits — being more or less open, for example. Relationship experiences matter, including partnership dynamics and loss, which is particularly salient in later life.

Contexts such as the workplace and school also shape opportunities for social contact; unemployed people may have fewer such opportunities. Neighborhoods and municipalities can facilitate or restrict social engagement through clubs or youth centers, and urban design matters — are there places to meet? At the societal level, cultural norms exert influence: Western societies are more individualistic, whereas Eastern societies tend to be more community‑oriented. Access to resources, technology, and digitalization also plays a role.

Regarding adolescents, there is an interesting study on social media’s role. It suggests social media tends to reduce loneliness among older adults, but to increase it among young people. I use social media myself and am generally technology‑friendly, but I do see risks for very young people, especially when most of their interactions are mediated through these platforms.

So this digital connectivity may actually promote loneliness among children and young adolescents because they lack established in‑person social ties.

That is what a study by Maike Luhmann indicates. At the same time, several newer studies, including meta‑analyses, show that older adults benefit from social media. One can readily imagine why: older adults maintain relationships and use these tools to arrange meetings or to keep up with the activities of children who live far away.

That tends to be beneficial. Even though we have focused on social media here, there is no single cause — reasons are multifaceted and can operate at the individual and immediate environment, the wider context, neighborhoods or municipalities, and the societal level. People do not live in a vacuum.

One last question about children and adolescents. During the COVID‑19 pandemic, they came into focus because of school closures and related disruptions. Is it possible that, since then, we have simply asked and researched more about loneliness in this group?

That is very likely, although children and adolescents were not the initial focus at the start of the pandemic. Older adults were at the forefront. We promptly began a telephone survey of more than 1,000 older adults, anticipating considerable loneliness and psychological stress.

What did we find? Older adults proved relatively stable and not significantly lonelier. We then conducted an in‑depth follow‑up, the so‑called qualitative study. In essence, older respondents told us: We have lived through a great deal; we have resources; we could contribute something to this difficult situation.

Only as the pandemic progressed did it become clear that children and adolescents were much more strongly affected. In retrospect, that is not surprising — they are still developing. Humans are social beings; without a social environment, we cannot thrive.

In Part 2, we discuss the health risks of loneliness and strategies.