Suicide remains a major public health concern with over 703,000 deaths occurring globally annually (WHO, 2021). Pathways to suicide are complex, involving many risk factors, with loneliness coming to the fore as one of the most prevalent in recent years (McClelland, 2020) and progress in predicting suicidal behaviour has not improved markedly in the last 55 years (Franklin et al, 2017).

Loneliness is improperly related to older age, but can and does occur across the lifespan. It emerges in the absence of good quality relationships, placing individuals at increased risk of social isolation and negatively impacting their health. As such, loneliness has gathered attention worldwide from public health organisations (Loneliness Taskforce, 2018) with up to 17% of the general population experiencing loneliness at some time in their lives (Beutel et al. 2017). In addition, loneliness has consistently been found to be associated with both suicidal ideation and behaviour, with different leading models suggesting this, such as the Integrated Motivational-Volition (IVM) model (O’Conner & Kirtley, 2018).

As it stands the evidence base suggests that loneliness is associated with suicide ideation and attempts, with some evidence for the effectiveness of interventions to address loneliness itself. However, there is no substantial evidence for the effectiveness of interventions to address both loneliness and suicidality. With all this in mind, it is theoretically possible to target loneliness to reduce suicidality, but that creates questions about context and meaning. The current study aims to investigate different types of loneliness (family, social and romantic) in relation to suicidal ideation and self-injurious behaviours with the hope of the results supporting the development of more nuanced, adaptive suicide prevention strategies to support the well-being of those at risk of self-harm.

Methods

This online cross-sectional study investigated three types of loneliness (family, romantic, social), as well as loneliness as a unidimensional construct (as is seen in most research as “global loneliness”) in relation to self-injurious thoughts and behaviours. Based on participant’s history of self-harm, they were allocated into one of three groups:

1. NH: No history of self-injurious thoughts or behaviour
2. SI: History of self-injurious thoughts but no history of self-injurious behaviour
3. SB: History of self-injurious behaviour (including suicidal attempt) regardless of any history of self-injurious thoughts

Data was collected using opportunistic sampling, with anyone 18 or over being eligible to participate and complete a survey. The study was promoted through academic websites, and personal and professional social media (e.g., Facebook, Twitter). The authors collected demographic details and measures including self-injury history (adapted from the Adult Psychiatric Morbidity Survey), suicidal ideation (The Suicide Probability Scale), global loneliness (self-report measure from UCLA), family, romantic and social loneliness scale (SELSA), depression (PHQ-9), defeat (The Defeat Scale) and entrapment (The Entrapment Scale).

Data was analysed using multinominal logistic regressions followed by pairwise post-hoc analyses. These were conducted using adjusted models controlling for age, gender and depression, then repeated controlling for the different types of loneliness. Participants who completed less than 75% of the survey measures were removed from the study, and missing data was handled using estimation-maximisation imputation techniques.

Results

In total, 582 participants participated in the study. Most of the sample were female (73%), 18 – 30 years old (80% vs. 17.5% 31 – 59 years old and 2.4% over 60), predominantly British (50%) and heterosexual (60%).

To what extent are loneliness, depression, defeat and entrapment associated with suicidal ideation?

• Suicidal ideation had a significant positive association with loneliness (global, family, romantic and social), depression, defeat and entrapment.

Which psychological factors distinguish between those with no history of self-injurious thoughts or behaviours, history of self-injurious thoughts only, and those with a history of self-injurious behaviour?

• The authors found that suicidal ideation significantly differentiated between self-injury history (NI, SI, SB) groups when controlling for all other variables (global, family, romantic and social loneliness, depression, defeat, entrapment).
• There were also significant differences in romantic loneliness scores between the SI and SB groups when controlling for all other variables.

Which, if any, forms of loneliness moderate the relationship between defeat and entrapment, and entrapment and suicidal ideation?

• No forms of loneliness had a significant moderation effect between defeat and entrapment.
• Family loneliness, romantic loneliness, and global loneliness were found to significantly moderate between entrapment and suicide ideation.
• There was no moderation effect of social loneliness on entrapment and suicidal ideation.

Does depression mediate the relationship between any form of loneliness and suicidal ideation, and if so, does the level of mediation vary?

• After controlling for demographics and other forms of loneliness:
  • Depression was observed to fully mediate between romantic loneliness and suicidal ideation
  • Depression was found to partially mediate between family and global loneliness in relation to suicidal ideation
  • Depression did not significantly mediate between social loneliness and suicidal ideation.

Conclusions

Distinct types of loneliness may have varying effects when looking at loneliness as a potential risk factor for suicidal ideation. While depression mediated the effect between global, family, and romantic loneliness with suicidal ideation, no significant effect was found regarding social loneliness. Romantic loneliness had an especially adverse association with depression and suicidal ideation.

The authors concluded that focussing on depressive symptoms may be helpful when addressing suicidal ideation in lonely individuals, though this may need to be adapted to the type of loneliness experienced by the individual. The results support the notion, that loneliness is a multifaceted concept and needs to be further explored.

Strengths and limitations

Overall, this paper provides interesting results. By considering loneliness types we may be able to, subject to confirmation from studies establishing causality, identify people at risk of suicidality and self-injurious thoughts and behaviours.

This study benefits from having clear aims and hypotheses, using validated measures and using a large sample. However, representativeness may be questioned as the majority of the sample was white, female, and young adults which poses the question – would these results be the same in different or more diverse populations? For instance, there is emerging evidence on the risk of suicidality in minoritised ethnic groups as a result of underreporting, stigma and discrimination (Coimbra et al, 2022). Thinking further about diversifying the sample, there is some data acquired that the authors didn’t examine closer, for example, sexuality. This could be particularly poignant as we know that LGBTQIA+ groups are at a higher risk of suicidality. In addition to this, when race/ ethnicity and sexual orientation intersect, it’s been shown to increase the risk of suicide. Transgender people are noted to be at a higher risk of anxiety and depression than the general public, as well as an increased risk of self-harm and suicidal ideation (Budge et al, 2013) and considering the recent vitriol and pincer attack on their identity from the government and mass media, these marginalised groups should be supported and seen in all research in this area.

A primary limitation of this study is its cross-sectional design. Longitudinal research is needed to better elucidate causality (e.g., do differing types of loneliness lead to suicidal ideation or do having suicidal ideations lead to further feelings of loneliness and reclusion) and build further the evidence base.

While the self-injury history measure was adapted from a validated scale, there is limited detail on how participants were scored to (i) establish ‘clinical history’ of self-injury and (ii) allocate them into groups. A further issue with the eligibility criteria not being detailed in the paper, we aren’t aware whether previous or existing mental health conditions were a prerequisite for taking part in the study. Clarity on this is important as it leads to ethical consideration of psychological safety and aftercare for addressing sensitive topics in potentially vulnerable groups.

Lastly, the reporting sometimes lacks clarity. For example: (i) table 2 is coded for the groups (NH, SI, SB) but there is no mention of the groups in the table (ii) the abstract states that the study recruited from May to October, but in the main body states recruitment was July to November (iii) the authors state that “Depression was observed to significantly mediate between all forms of loneliness in relation to suicidal ideation” but later correct this highlighting the lack of moderation for social loneliness.

Implications for practice

This paper is a good jumping-off point for researchers and clinicians. The authors highlight that clinicians could focus on depression for those who present with suicidal ideation and loneliness; but that if clients report experiencing romantic loneliness, reduction in ideation may be resistant to lessening. There is a 5-year plan for a National Suicide Prevention Strategy for England (2023 – 2028) which means whilst we must continue to grow our body of evidence, we must act concurrently. There are a few other immediate clinical implications we can consider.

As mentioned above, we know loneliness is often only associated with older age, yet the dominant margin of this sample is young adults. This is a good reminder to consider our unconscious biases and potential blind spots. When assessing service users who report a history of or present suicidality in any capacity, it’s important we stay in the moment and connect, screening for loneliness in initial assessments, thinking systemically and how these might present differently across the lifespan, asking reflexive questions about established relationships and their relationship status. Whilst this sounds obvious, I think in a lot of instances, we can be triggered into following safeguarding protocol in a perfunctory manner. This is of course essential, but it shouldn’t be at the expense of being exploratory.

A strength of the research is that it reinforces the growing body of research on loneliness and associated poor mental health (Hawkley et al., 2022). As clinicians we can think about the stigma around loneliness in different demographics and how naming it can normalise the experience for service users, potentially reducing shame (Barretto et al, 2022). We can think about individual-level interventions (e.g. addressing maladaptive cognitions, reframing loneliness and associated thoughts and behaviours, psychoeducation around social skills) and think about linking individuals with their wider communities (e.g. local and context-dependent support groups, third sector organisations such as Men’s Sheds, or for romantic loneliness specifically SLAA).

Statement of interests

Liam is a trainee clinical psychologist. No conflicts of interest.

Links

Primary paper

Other references

Barreto M., Victor, C., Hammond, C., Eccles, A., Richins, M.T., & Qualter, P. (2021). Loneliness around the world: Age, gender and cultural differences in loneliness. Personality and Individual differences, 169

Coimbra, B. M. et al. (2022) https://www.sciencedirect.com/science/article/pii/S2352827322002622

Coyle, C. E., & Dugan, E. (2012). Social isolation, loneliness and health among older adults. Journal of aging and health, 24(8), 1346–1363.   doi.org/10.1177/0898264312460275.

Kidd, G., Marston, L., Nazareth, I., Osborn, D., & Pitman, A. (2023). Suicidal thoughts, suicide attempt and non-suicidal self-harm amongst lesbian, gay and bisexual adults compared with heterosexual adults: analysis of data from two nationally representative English household surveys. Social Psychiatry and Psychiatric Epidemiology.

McClelland, H., Evans, J. J., & O’Connor, R. C. (2021). Exploring the role of loneliness in relation to self-injurious thoughts and behaviour in the context of the integrated motivational-volitional model. Journal of Psychiatric Research, 141, 309–317. https://doi.org/10.1016/j.jpsychires.2021.07.020

O’Connor RC, Kirtley OJ. (2018) The integrated motivational-volitional model of suicidal behaviour. Phil. Trans. R. Soc. B 373: 1754  DOI: 10.1098/rstb.2017.0268  http://dx.doi.org/10.1098/rstb.2017.0268

Office for National Statistics (2018). Measuring loneliness: guidance for use of the national indicators on surveys.

Photo credits

• Photo by Aaron Burden on Unsplash
• Photo by Cody Black on Unsplash