Maternal depressive symptoms trajectories and harsh parenting: the mediating role of maternal quality of life in the 2004 Pelotas Birth Cohort.

Objective: To study the impacts of maternal depressive symptoms trajectories and harsh parenting and explore if the maternal quality of life mediates this association.

Methods: We used data from the 2004 Pelotas Birth Cohort, a population-based longitudinal study from Pelotas, Brazil (N = 3285 mothers, complete cases analysis). We used the Edinburgh Postnatal Depression Scale to assess maternal depressive symptoms and the trajectories from three months until the 11-year follow-up were calculated using a group-based modelling approach. Psychological and physical aggression were measured using the Parent-Child Conflict Tactics Scale. Maternal quality of life was measured by the question "How is your quality of life?". Data were analyzed using path models in Mplus.

Results: Our findings showed that all maternal depressive symptoms trajectories increased the frequency of psychological and physical aggression at early adolescence when compared to the reference group. Mediation analysis indicated that maternal depressive symptoms led to low levels of perceived maternal quality of life, which in turn was associated with the increased use of harsh parenting. The proportion of total effect explained by maternal quality of life ranged from 4.04% (0.00%-5.58%) to 16.31% (10.88%-19.10%).

Conclusion: Our findings support the evidence showing that maternal depressive symptoms are associated with harsh parenting within a longitudinal framework from a middle-income country. Our results also suggest that one mechanism underlying this association is a women's lower perceived quality of life.