Loneliness can feel like being the only elf left out of the workshop: even though there are people around, you still feel like no one sees you. People often think of loneliness as a temporary feeling that comes and goes. But what if it’s not so short-lived for some young people? What if feeling disconnected as a teenager has a long-term effect on mental health, changing not only how people feel but also how they think about life?
Before diving into the research, it’s important to clear up a common misunderstanding: being alone is not the same as being socially isolated. Social isolation is objective and measurable by the lack of social contact, but loneliness is subjective. It is a feeling that comes from thinking that your relationships aren’t as meaningful or fulfilling as you’d like them to be.
Did you know that around 1 in 10 adolescents experience severe loneliness? Loneliness is also increasingly recognised as being linked to mental health and the risk of suicide. Previous research has shown that feeling lonely can make you think about suicide, irrespective of your income, living status, and mental distress. One blog said that this link might be stronger among younger people and men (Eager, 2022).
Loneliness is also a major part of important psychological theories about suicide. The Interpersonal-Psychological Theory of Suicide posits that feelings of disconnection from others, referred to as thwarted belongingness (the sense of not truly belonging anywhere), alongside the feeling of being a burden, contribute to thinking about suicide. But to go from thoughts to actions, you need more than just that, like being able to tolerate pain better or being less afraid of death. This shows that loneliness is only one part of a much bigger picture.
Loneliness in adolescence is common, but when it becomes chronic, it may have lasting consequences for mental health and well-being.
Methods
The Add Health study is a school-based, long-term survey conducted in the US that has tracked thousands of youth throughout time. Approximately 17,000 teenagers aged 11 to 21 were included and followed into adulthood. UCL researchers used the Add Health study data to examine whether loneliness in adolescence was associated with suicidal thoughts at two time points: 6-year and 13-year follow-up.
The researchers also accounted for factors such as depressive symptoms and past-year suicidal thoughts. This was to help make sure that loneliness itself is what caused suicidal thinking, and not any other factor.
Results
Sample
Data from 17,751 young people were included in the study. At the beginning of the study, about 1 in 12 (8%) reported higher loneliness. Women, 14–18-year-olds, as well as those from minority ethnic backgrounds, were more likely to report feelings of loneliness.
Loneliness and suicidal thoughts (6-year follow-up and 13-year follow-up)
At the 6-year follow-up, young people who had previously reported loneliness had almost twice the odds of suicidal ideation compared to those who did not. However, this association was not statistically significant when researchers considered other variables, in particular depression, indicating that loneliness might not be the only factor contributing to the elevated risk.
At the 13-year follow-up, young people who had previously reported loneliness had 36% higher odds of suicidal ideation compared to those who did not; however, this finding was borderline statistically significant.
Final results
| Outcome | 6 years follow-up | 13 years follow-up |
| Suicidal thoughts | Elevated odds; no longer significant after adjustment for depression. | Small link after adjustment |
| Suicide attempts | No link | No link |
The role of depression and other factors
Subsequent investigation revealed that the relationship between suicide ideation and loneliness was predominantly explained by pre-existing depressive symptoms rather than just loneliness alone.
Overall, the results indicate that loneliness may be related to suicidal thoughts later in life, but this relationship is weak and mostly explained by depression. Additionally, loneliness does not seem to increase the likelihood of suicide attempts.
Loneliness in adolescence was linked to later suicidal thoughts, but much of this association faded after accounting for depression and other factors.
Conclusions
- Adolescent loneliness is associated with an increased risk of suicide ideation in later life, although this relationship is weak and diminishes significantly when other variables are included.
- There is no proof that loneliness on its own raises the likelihood of suicide attempts at the 6-year or the 13-year follow-up.
- The results imply that depression, rather than loneliness alone, plays a major role in explaining the association between loneliness and suicide ideation.
- Overall, the findings suggest that there may be a need for interventions to address both depression and loneliness.
Loneliness alone may not explain later suicidality, highlighting the importance of broader mental health factors such as depression.
Strengths and limitations
A key strength is the longitudinal design of the Add Health cohort, which allows researchers to examine whether loneliness precedes later suicidal ideation rather than relying on a single time point. The study also benefits from a large sample size and relatively high retention, reducing (but not removing) risk of attrition bias.
However, there are important limitations. A major issue is measurement quality: loneliness and suicidal thoughts were assessed using single-item self-report questions, which oversimplify complex constructs and increase the risk of misclassification bias.
There is also likely residual confounding, particularly from depression and wider social factors. Although the study adjusted for baseline depressive symptoms, this may not fully capture how depression varies in severity or over time, meaning some effects may still overlap with loneliness. Other factors such as socioeconomic deprivation, family-related stressors, and trauma were also not fully included, despite being linked to both loneliness and suicidal thoughts. Because of this, the relationship seen may partly reflect these unmeasured influences rather than loneliness alone.
Finally, because loneliness was only measured at one point, the study cannot distinguish between chronic vs temporary loneliness, which may have very different impacts on mental health outcomes.
While the study’s large, nationally representative sample is a key strength, its reliance on single-item measures of loneliness and suicidality limits how confidently we can interpret the findings.
Implications for practice
So what are the next steps, and what does this mean for future practice and research?
These outcomes suggest that loneliness may still be a significant early sign of distress. Recognising adolescents struggling with loneliness could assist professionals in identifying individuals who are more likely to face mental health issues in the future. Early identification of depression and loneliness, in settings such as educational institutions, may enable more prompt and focused assistance.
However, interventions should be cautious not to treat loneliness in isolation, but rather as part of a comprehensive mental health profile, since the connection between loneliness and suicidal ideation was mostly explained by depressive symptoms.
It is also important to address both depression and loneliness to decrease suicidal thoughts. Therefore, strategies that integrate evidence-based mental health interventions with components of social support may be particularly effective.
Schools, universities, and youth mental health services should focus more on social connectedness and belonging, particularly during adolescence when peer relationships become especially important.
However, the lack of a connection with suicide attempts implies that lowering loneliness might not be enough to stop more serious consequences, underscoring the necessity of multi-layered preventative strategies.
Future research should investigate whether chronic loneliness, rather than temporary loneliness, is more strongly associated with suicidality over time. Additionally, longitudinal research should try to better distinguish the direction of effects, namely, whether loneliness causes depression or whether early depressive symptoms cause loneliness.
Schools and youth services may benefit from treating loneliness as a warning sign, not a standalone problem.
Statement of interests
As MSc Clinical Mental Health Sciences students at UCL, we want to clarify that while some individuals involved in the discussed research are UCL faculty, we have no direct involvement in the study, its review, or publication. This blog was created independently for our coursework and reflects our interpretation. We have no conflicts of interest beyond our academic relationship with the study. We acknowledge the use of ChatGPT to proofread the final draft.
Contributors
Thanks to the UCL Mental Health MSc students who wrote this blog from the Wood Student Group: Anna Mylona, Annabel Gerard-Pearse and Jana Sobh.
UCL MSc in Mental Health Studies
This blog has been written by a group of students on the Clinical Mental Health Sciences MSc at University College London. A full list of blogs by UCL MSc students can be found here.
We regularly publish blogs written by individual students or groups of students studying at universities that subscribe to the National Elf Service. Contact us if you’d like to find out more about how this could work for your university.
Edited by
Dr. Dafni Katsampa.
Links
Primary paper
Jin, Y., Kieslich, K., Hall, A., & Pitman, A. (2026). Association between Loneliness and Suicidal Thoughts and Attempts in Adolescence and Young Adulthood: A Longitudinal Analysis of a Nationally Representative US Sample. Archives of Suicide Research, 30(1), 66–79. https://doi.org/10.1080/13811118.2025.2489159
Other references
Eager, S. (2022, June 20). Does the link between loneliness and suicide vary for men and women? National Elf Service. https://www.nationalelfservice.net/mental-health/suicide/loneliness-suicidal-ideation/
Surkalim, D. L., Luo, M., Eres, R., Gebel, K., Van Buskirk, J., Bauman, A., & Ding, D. (2022). The prevalence of loneliness across 113 countries: systematic review and meta-analysis. BMJ, 376, e067068. https://doi.org/10.1136/bmj-2021-067068
