Trajectories of social isolation and depressive symptoms in mid- and later life: a parallel process latent growth curve analysis

Objectives Social isolation has subjective and objective dimensions. This study explored the change trajectories of both dimensions of isolation and depressive symptoms and their interrelationships in terms of levels and changes over time.Methods Data were drawn from the 2006–2018 Health and Retirement Study, involving a nationally representative sample of middle-aged and older adults (N = 7890). Parallel process latent growth curve models were used.Results Over time, objective isolation displayed a non-linear upward trend, subjective isolation displayed a non-linear downward trend, and depressive symptoms remained relatively stable. More objectively isolated people experienced smaller increases in objective isolation and more subjectively isolated people experienced smaller decreases in subjective isolation. Such negative intercept-slope associations were not observed for depressive symptoms. Net of sociodemographic characteristics, physical disabilities, functional limitations, and chronic diseases, each isolation dimension was associated with the level of depressive symptoms. But only the rate of change in subjective isolation was positively associated with that of depressive symptoms.Conclusion The initial level of objective isolation may be one of the common origins of subjective isolation and depressive symptoms. Recognition of such shared origins is important in mitigating the synergistic and deleterious effects of loneliness and depression in middle-aged and older adults.