Five-year changes in loneliness and mental health among adults 41-85 years: the Doetinchem Cohort Study.

Background: Both loneliness and mental health represent important public health themes with stable or even worsening population figures. The association between loneliness and mental health is cross-sectionally well-established, but longitudinal studies are scarce. The aim of this study is to explore the individual changes in loneliness and mental health and the relation between these changes.

Methods: We used data from wave 5 (years: 2007-2012, n: 4016) and wave 6 (years: 2013-2017, n: 3437) of the Doetinchem Cohort Study, consisting of participants aged 41-86 years. Loneliness was measured using the De Jong-Gierveld 6-item Loneliness Scale and mental health was measured with the 5-item Mental Health Inventory. We assessed changes in loneliness and mental health over a 5-year period. Generalised estimating equations and linear regression were performed to determine the longitudinal association. Associations were adjusted for various sociodemographic, lifestyle and health factors.

Results: Over a 5-year period, 23.4% experienced a change in loneliness and 9.7% in mental health.Higher levels of loneliness were significantly associated with poor mental health both cross-sectionally and over time (β:-3.56, 95% CI: -3.79 to -3.32). Increasing feelings of loneliness were associated with worsening mental health, and decreasing feelings of loneliness were associated with improving mental health (β:-2.35, 95% CI: -2.61 to -2.08).

Conclusion: The high rate of individual changes in loneliness, combined with the association between changes in loneliness and changes in mental health, shows a possible potential in improving poor mental health by designing public health interventions aimed at reducing feelings of loneliness.