Research That Matters (January 17 - 20, 2008)

PURPOSE: Postpartum depression is a major health concern for many women and their families. Without early detection and treatment, depression may continue beyond the first year of childbirth, especially for those experiencing material hardship and related chronic stress. Marriage has been described as protective against emotional distress including depression. Studies have found that married mothers have better mental health outcomes as compared to unmarried mothers. However, this variation may be due to uncontrolled selection factors that influence the likelihood of marriage. In addition, few studies have considered different types of relationships, such as couples who are unmarried but cohabiting. Using longitudinal data from a nationally representative sample of low-income mothers and a propensity score matching (PSM) approach, this study builds upon current research to isolate and estimate the effect of marital status on depression. This study hypothesizes that no significant difference in depression will be observed between married and cohabiting mothers.

METHODS: The sample for this analysis included 4,898 mothers who participated in the Fragile Families and Child Wellbeing Study, a longitudinal survey designed to examine the conditions and capabilities of unmarried and married parents and their children in large U.S. urban cities. The current analysis includes data at baseline and at the one and three year follow-up points. To address potential selection bias in estimating the impact of marital status on depression, PSM is employed to generate comparison groups of married and cohabiting mothers with equivalent distributions across relevant selection factors. The resulting matched sample includes 975 married mothers and a comparison group of 981 cohabiting mothers. After generating the matched groups, multiple logistic regression is used to estimate the effect of marital status at year one on the probability of being depressed at year three.

RESULTS: The mean age of participants is 26 years, with 48% identifying as African American, 26% as Latino, and 21% as white. Mothers have a mean annual household income of $31,000, with at least a high school degree or graduate equivalency diploma. At baseline, 24% of mothers identified as being married and 36% as cohabiting with a partner but not married. Preliminary results suggest that the hypothesized relationship between marital status and depression is supported. Using PSM, mothers who reported being married are more likely to be depressed, compared to mothers cohabiting with a partner. However, this difference is not statistically significant (OR=1.38, 95% CI=.80-2.39).

IMPLICATIONS: These findings suggest that marriage by itself does not indicate improved depression, as prior literature has reported. Given the limitations of selection biases in being married and cohabiting, the use of PSM allows for a more accurate estimation of depression. Many studies and recent Healthy Marriage Initiative policies have often targeted marriage as an outcome, especially for “fragile” families. Results from this study indicate that other factors, such as relationship quality and social support systems, which may moderate the relationship between marital status and mental health outcomes are more appropriate targets for interventions and policies that are aimed at reducing depression among new mothers.