Trajectories of impairment, social support, and depressive symptoms in later life.

OBJECTIVE Research has increasingly focused on the dynamic nature of disability and depressive symptoms in later life. Little research, however, has modeled disability and depressive symptoms as dynamic, related processes. Furthermore, virtually no research has considered social support as dynamic across age. Here, we investigate the relationship between long-term patterns of disability, perceived and received social support, and depressive symptoms in later life. METHODS We use random coefficient (growth) models of four waves of Duke Established Populations for Epidemiologic Studies of the Elderly data to determine whether disability, support, and depressive symptoms follow linear trajectories across age and whether support mediates the relationship between disability and depressive symptoms. RESULT The results show that (a) trajectories of disability are strongly related to trajectories of depressive symptoms and (b) trajectories of perceived support mediate the relationship between trajectories of disability and depressive symptoms, whereas trajectories of received support do not. DISCUSSION Disability, social support, and depressive symptoms are strongly interrelated processes in later life. Our results are consistent with previous research in showing that perceived, rather than received, support mediates the relationship between disability and depressive symptoms, but our results extend previous research in showing that this mediation occurs across time.