Reducing loneliness among the elderly can prevent future depressive symptoms

Older adults with higher levels of loneliness were at greater risk for more severe depressive symptoms, according to the results of a population-based cohort study published in The Lancet Psychiatry.

“Many studies have looked at the relationship between loneliness and depression in the elderly, but these studies had limitations,” Siu Long Lee, MSc, of the Division of Psychiatry at University College London and colleagues wrote. “There have been several cross-sectional studies, but it is impossible to rule out the reverse causation in studies with a cross-sectional design. Longitudinal studies are essential to establish whether loneliness precedes depressive symptoms, which is a necessary condition for identifying loneliness as a potentially causative, and therefore identifiable, risk factor for depression. “

Lee and colleagues sought to determine whether loneliness was linked to more severe symptoms of later depression by analyzing seven waves of data collected once every 2 years between 2004 and 2017 of adults aged 50 and over included in English. Longitudinal Study of Aging. Baseline loneliness, as measured by the short 1980 UCLA Loneliness Scale review, served as an exposure. Depression severity measured at six successive time points using the eight-item version of the Center for Epidemiologic Studies Depression Scale (CES-D) was the primary outcome. Researchers used multilevel linear regressions for analysis, which they corrected before and after for social isolation, social support, polygenic risk scores, and other sociodemographic and health-related confounders. Diagnosis of depression, measured using a binary version of the CES-D.

Comprehensive data on exposure, outcomes and confounding factors were available for 4,211 eligible participants. The results showed a one-point increase in the loneliness score linked to a 0.16 (95% CI, 0.13-0.19) increase in the depressive symptom severity score after all adjustments. Researchers estimated an attributable population fraction for loneliness-related depression of 18% (95% CI, 12-24) at 1 year of follow-up and 11% at final follow-up. This suggested that between 11% and 18% of depression cases could have been prevented if the loneliness was eliminated, Lee and colleagues noted. Furthermore, after 12 years of follow-up, associations between loneliness and depressive symptoms remained; however, the effect size was smaller with longer follow-up.

“While coping with loneliness effectively will be a complex task, it has important potential for reducing or even preventing future depressive symptoms in older adults,” Lee and colleagues wrote.