Objectives To investigate the mechanisms through which marital status exerts long-term effects on depressive symptoms among women and to evaluate the relative importance of psychological, social and financial resources in mediating this relationship.

Methods Data came from 6107 female respondents to a nationally representative longitudinal data set from the USA (National Survey of Families and Households 1987–1988/1992–1994). Mediation was investigated using semi-longitudinal structural equation modelling and bias-corrected bootstrapped CIs. Latent constructs with multiple indicators were used to measure depressive symptoms, primary and secondary social integration and self-esteem.

Results The total effect of marital status on subsequent depressive symptoms was statistically significant for all marital statuses relative to those in first marriages controlling for age, education, race, number of children younger than 5 in the household, T1 depressive symptoms and marital status transitions between waves; all groups experienced higher levels of depressive symptoms than those in first marriages. These effects were completely mediated for never-married women and partially mediated for separated/divorced, widowed and cohabiting women. Adjusted household income was the largest mediator for the separated/divorced, widowed and never-married, but primary social integration also played a role. Self-esteem was the only significant mediator for the remarried and cohabiting and was also important in explaining differences between the first-married and separated/divorced.

Conclusion This study demonstrates that the reasons why marital status has an influence on subsequent depressive symptoms varies depending on the specific marital status being compared with the married.