Longitudinal relationships between depressive symptoms and health in normal older and middle-aged adults.

Comorbidity between health and depression is salient in late life, when risk for physical illness rises. Other community studies have not distinguished between the effects of brief and long-standing depressive symptoms on excess morbidity and mortality. S. Cohen and M. S. Rodriguez's (1995) differential hypothesis of pathways between depression and health was used to examine the relationships between health and depression in a prospective probability sample of 1,479 community-resident middle-aged and older adults. Findings suggest that different durations of depressive symptoms have different relationships to health. Health had an impact on short-term increases in depressive symptoms but depressive symptoms had a weaker impact on health. The reciprocal impact was indistinguishable from the health influence on depression. In contrast, longer term depressive symptoms had a clear impact on health. The results imply that physical illness can affect depressive states; depressive traits but not states can affect illness.