Landmark research has shown that loneliness is associated with later ill health, including increased risk of later mental or physical illness, such as coronary heart disease (Valtorta et al., 2016) or psychological distress, such as depression and self-injury (McClelland et al. 2020). Durkheim (1952) stated that an integral composite for human survival was having a connection to something that transcends oneself i.e., having a sense of purpose. Whether that is caring for others (e.g., children, parents… the village cat) or setting goals (e.g., mastering a skill, striving for an accolade). Indeed, loneliness and lack of purpose in life are often argued to be interlinked, with many vocations, hobbies and occupations commonly having a social element to them.

Although public awareness of loneliness was rising before the COVID pandemic and lockdowns became part of our everyday language, the awareness of loneliness and its implications on wellbeing were unavoidable during the pandemic. Consequently, interventions to reduce such lonely experiences have been developed to promote social connectivity (e.g., The Chatty Café Scheme where lonely people can strike up conversations with one another over a cup of tea), but what is the rationale behind this? Why not use distraction, or thought challenging to drown out the negative thoughts and feelings that loneliness invokes?

Sutin and colleagues (2022) addressed this question by exploring the association between loneliness and a sense of purpose in life.

Methods

Secondary data analysis from 36 participant cohorts, collected across ten studies, were included in this study. The association between purpose in life and loneliness were investigated in the following ways:

• Cross-sectionally: measuring loneliness and purpose in life at the same time.
• Longitudinally: loneliness and purpose in life was measured across several timepoints spanning several months to 15 years, to identify whether the association between the two variables was associated over time.
• Moderating effects: to identify whether the association between loneliness and purpose in life is influenced by (a) age, and (b) psychological distress.

To conduct the analysis, the data from all ten studies was investigated using meta-analysis; a specific type of analysis specifically designed for identifying overall effect sizes based on data collected from several studies.

Due to the paper drawing on data from various other databases, different measures were used to measure the same variable. Sense of purpose was measured continuously from one of four different measures including one 7-item scale and three single-item variables. Responses ranged from 3- to 7-point scales. Additionally, loneliness was measured using one of ten different measures, half of which were a single item-measure. Responses ranged from a dichotomous response (yes or no) to a seven-item response. Continuous data was used for cross-sectional data analysis, which was dichotomised for inclusion in longitudinal analysis (lonely: yes/ no). All participants included completed a depressive symptoms severity measure and provided their sociodemographic information such as age, sex, race, and level of education.

Data from 135,227 participants aged 18-109 years old were included in this study. Participants with national representation across four continents.

Results

Cross-sectional findings:

• 135,227 participants from 36 cohorts (ten studies) were included in the analyses
• Greater sense of purpose was linked with lesser loneliness in all cohorts
• Severity of depressive symptoms significantly moderated the association between sense of purpose and loneliness in 28 of the 39 studies
• The association between sense of purpose and loneliness was not moderated by age.

Longitudinal findings:

• 28 cohorts were included in the analyses
• Across all studies, those who did not have a sense of purpose were significantly more likely than those who did have a sense of purpose, to report feeling lonely at a later timepoint
• Neither age nor distress moderated the association between sense of purpose and loneliness.

Conclusions

The authors sum up their conclusions early:

Across 36 cohorts that ranged in age from 18 to 109, there was clear evidence for a relation between sense of purpose in life and loneliness: Individuals who perceived more purpose in their lives felt less lonely. The meta-analytic mean effect was -0.31, which indicates a moderate effect size.

Greater purpose in life was associated with less loneliness. Psychological distress was a strong moderator within the cross-sectional analysis.

Strengths and limitations

The study presented certain strengths:

• Firstly, the findings here are consistent with new interventions being tested to reduce loneliness (e.g., Weiss et al. 2020) and other existing current literature, therefore it is likely that these findings are reliable.
• Second, Sutin and colleagues investigated the association between sense of purpose in relation to loneliness both cross-sectionally and prospectively. The latter approach is a particular strength as cross-sectional associations can be coincidental or induced through other factors. Alternatively, prospective investigations enable more confident inferences between cause and effect. This review has shown that in numerous studies, greater sense of purpose (the cause) was significantly associated with later, lesser loneliness (the effect).
• Finally, the overall participant sample was very large and represents a large proportion of the Western world. Thus, this increasing the generalisability of the evidence.

The study does not come without its limitations and the authors acknowledge this:

• The studies included in this meta-analysis were not identified systematically and a large amount of data was removed from the longitudinal analysis as, instead of controlling for baseline loneliness, the authors removed anyone who reported loneliness at the first time-point.
• As with most studies, low-middle income countries and Africa were under-represented.
• Finally, there was a lack of discussion of how these findings fit with existing psychological theory.

Implications for practice

Those presenting in clinics with loneliness, or where loneliness may be symptomatic of a mental illness (e.g., depression), may benefit from exploring their sense of purpose in life. Use of models such as Self-Determination Theory can help the patient or individual to understand the causes and maintaining factors of their loneliness. Equally, motivational interviewing or cognitive-behavioural techniques (especially thought challenging, such as fact checking and black and white thinking; Cacioppo et al., 2015) may help individuals re-engage in activities which give them a purpose in life, therein having connectivity with something, or someone, beyond themselves.

Statement of interests

No conflict.

Links

Primary paper

Sutin, A.R., Luchetti, M., Aschwanden, D., Lee, J.H., Sesker, A.A., Stephan, Y. and Terracciano, A., 2022. Sense of purpose in life and concurrent loneliness and risk of incident loneliness: An individual-participant meta-analysis of 135,227 individuals from 36 cohorts. Journal of Affective Disorders, 309, pp.211-220. https://doi.org/10.1016/j.jad.2022.04.084

Other references

Cacioppo, S., Grippo, A.J., London, S., Goossens, L. and Cacioppo, J.T., 2015. Loneliness: Clinical import and interventions. Perspectives on Psychological Science, 10(2), pp.238-249. https://doi.org/10.1177/174569161557061

Durkheim (1952) cited in Thorlindsson, T., & Bjarnason, T. (1998). Modeling Durkheim on the micro level: A study of youth suicidality. American sociological review, 94-110. https://doi.org/10.2307/2657479

McClelland, H., Evans, J. J. , Nowland, R., Ferguson, E. and O’Connor, R. C. (2020) Loneliness as a predictor of suicidal ideation and behaviour: a systematic review and meta-analysis of prospective studies. Journal of Affective Disorders, 274, pp. 880-896. https://doi.org/10.1016/j.jad.2020.05.004

The Chatty Café Scheme. https://thechattycafescheme.co.uk/

Valtorta, N. K., Kanaan, M., Gilbody, S., Ronzi, S., & Hanratty, B. (2016). Loneliness and social isolation as risk factors for coronary heart disease and stroke: systematic review and meta-analysis of longitudinal observational studies. Heart, 102(13), 1009-1016. http://dx.doi.org/10.1136/heartjnl-2015-308790
Weiss, L. A., Oude Voshaar, M. A., Bohlmeijer, E. T., & Westerhof, G. J. (2020). The long and winding road to happiness: A randomized controlled trial and cost-effectiveness analysis of a positive psychology intervention for lonely people with health problems and a low socio-economic status. Health and quality of life outcomes, 18(1), 1-17. https://doi.org/10.1186/s12955-020-01416-x

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