Longitudinal Reciprocal Relationships Between Family Functioning and Depression Among Perinatal Women: Disentangling Between‐Person and Within‐Person Effects

ABSTRACT Previous research has suggested that family functioning is associated with perinatal depression; however, few longitudinal studies have explored whether this association is bidirectional, particularly at the within‐person level. Drawing on family systems theory and the interpersonal model of depression, this study investigated the longitudinal reciprocal relationships between family functioning and depression throughout the perinatal period, disentangling between‐person and within‐person effects. A total of 1053 perinatal women ( M age = 27.26 years, SD = 3.24, range = 18−41) were recruited at baseline and assessed across seven waves spanning early pregnancy to 12 months postpartum. Random intercept cross‐lagged panel modelling indicated that family functioning and perinatal depression were negatively correlated at the between‐person level ( r = −0.498, p < 0.001). At the within‐person level, their cross‐lagged effects were non‐significant from early pregnancy to 1 month postpartum ( β s = [−0.081, 0.104], p s > 0.05), but became significantly negative between 1 and 12 months postpartum ( β s = [−0.209, −0.125], p s < 0.05). Specifically, during the postpartum period, deteriorations in family functioning predicted subsequent increases in depression ( β s = [−0.163, −0.125], p s < 0.05), while elevated depression predicted subsequent declines in family functioning ( β s = [−0.209, −0.146], p s < 0.05). These findings extend our understanding of the dynamic interplay between family functioning and perinatal depression and underscore the postpartum period as a critical window for intervention, during which targeting either family functioning or depression may yield cascading benefits for maternal and family well‐being.