Disentangling the Longitudinal Relationship between Loneliness and Depressive Symptoms in U.S. Adults Over 50.

OBJECTIVES: A seminal study on loneliness and depression suggested that loneliness influences depression more than the reverse. However, the study's analytic method has since been criticized for failing to account for the trait-like nature of variables. This study aimed to examine the longitudinal relationship between loneliness and depressive symptoms while accounting for the trait-like nature of both variables.

METHODS: Data (n = 16,478) came from the Health and Retirement Study (2006-2016). Measures included the Hughes Loneliness Scale and a modified Center for Epidemiologic Studies Depression scale (loneliness item omitted). Analyses consisted of random intercepts cross-lagged panel models (three time-points evenly spaced across eight years).

RESULTS: There was evidence that loneliness and depressive symptoms are trait-like and these trait-like components are strongly associated. There was not evidence of cross-lagged effects between loneliness and depressive symptoms.

CONCLUSIONS: A tendency toward loneliness corresponded with a tendency toward depressive symptoms. However, deviations in one's typical level of loneliness did not predict deviations in one's typical level of depressive symptoms or vice-versa. These findings do not support past assertions that loneliness shapes subsequent depression more than the reverse.

CLINICAL IMPLICATIONS: By middle to late adulthood, loneliness and depressive symptoms are trait-like phenomena that are strongly associated.