The Etiology of Maternal Postpartum Depressive Symptoms: Childhood Emotional Maltreatment, Couple Relationship Satisfaction, and Genes

There is a call for integrative studies examining the roles of biological and psychosocial factors and their interrelations in shaping maternal postpartum psychopathology. Using longitudinal data from 198 primiparous mothers, we tested a biopsychosocial model for the etiology of maternal postpartum depressive symptoms that integrated childhood emotional maltreatment, couple relationship satisfaction, and oxytocin and dopamine D4 receptor genes (i.e., OXTR rs53576 and DRD4). Results indicate (a) two indirect effects from childhood emotional maltreatment and DRD4 to depressive symptoms at 1 year postpartum through couple relationship satisfaction at 6 months postpartum; (b) an interactive effect between DRD4 and couple relationship satisfaction at 6 months postpartum in predicting depressive symptoms at 1 year postpartum, which is in concert with the differential susceptibility hypotheses; and (c) no mediating effects or moderating effects (after adjusting for multiple testing with Bonferroni correction) involving OXTR rs53576. Notably, all associations were identified after controlling for several key covariates (e.g., maternal prenatal depressive symptoms). Last, robustness of the currently identified interactive effect involving DRD4 was demonstrated by an extensive set of additional analyses considering the effects of rGE, G × Covariates, and/or E × Covariates. Taken altogether, this study represents one of the initial efforts for a more sophisticated portrayal of how nature and nurture forces may work in conjunction with each other to shape new mothers' psychopathology. Yet given the current modest sample size and candidate gene approach, our findings are preliminary, should be cautiously interpreted, and need to be replicated with more rigorous designs.