Depression as a moderator and a mediator of marital quality's effect on older adults' self-rated physical health.

BACKGROUND

Depression and marital quality are both established correlates of physical health for older adults. However, there is a lack of research on the interaction between depression and marital quality on physical health, and on depression's role as a mediator of the mechanism by which marital quality affects physical health.

OBJECTIVE

This study aims to test the moderation and mediation effects of depression on marital quality's impact on older adults' self-rated physical health.

METHOD

Data from the National Social Life, Health, and Aging Project (Wave 2) (N = 2118) were used to test a latent moderated mediation structural equation model. Marital quality was constructed as a latent variable with indicators measuring its various aspects.

RESULTS

Depression had a significant moderating effect (β = .17, SE = .04, p <  .001, 95% CI [.08, .25]) on marital quality's impact on self-rated physical health: when the level of depression was low, higher marital quality was strongly associated with better self-rated physical health, but when the level of depression was high, higher marital quality became slightly associated with poorer self-rated physical health. Moreover, depression was a significant partial mediator (β = -.27, SE = .03, p <  .001, 95% CI [-.33, -.21]) of the effect of marital quality on self-rated physical health.

CONCLUSIONS

Depression plays an important role in explaining the mechanism by which older adults' marital quality affects their self-rated physical health. For marital quality to positively affect physical health, older adults need to attend to their personal mental health needs.