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.

<bold>Background: </bold>Sense of purpose, the feeling that one's life is goal-oriented and driven, tends to be protective for psychological health. Less is known about its relation with social health, particularly loneliness. We test whether the cross-sectional association between purpose and loneliness is replicable and whether purpose protects against the development of incident loneliness over time.<bold>Methods: </bold>Participants from 36 cohorts (total N = 135,227; age range 18-109) reported on their sense of purpose, loneliness, and psychological distress. Follow-up measures of loneliness were available in 28 cohorts that ranged from six weeks to 15 years. Prospective, random-effect meta-analysis was used to summarize the cross-sectional and longitudinal associations from each cohort.<bold>Results: </bold>Sense of purpose was associated significantly with less loneliness in all 36 cohorts, controlling for sociodemographic factors (meta-analytic mean effect estimate = -0.31, 95% CI = -0.34, -0.29, p < .001). This association was stronger among participants experiencing concurrent severe psychological distress. Sense of purpose was protective against the development of new incident loneliness (meta-analytic mean hazard ratio estimate = 0.85, 95% CI = 0.82, 0.87, p < .001). Age did not moderate any of the associations.<bold>Limitations: </bold>Limitations include the lack of lower-income countries. The mechanisms that explain this association also need to be identified in future research.<bold>Conclusions: </bold>Sense of purpose is associated with less loneliness and with protection against developing loneliness over time, associations that replicated across cohorts from North America, South America, Europe, and the Middle East. Sense of purpose may be a useful target of intervention to prevent or reduce loneliness, especially among individuals suffering from psychological distress. [ABSTRACT FROM AUTHOR]