While risk factors for children’s internalizing and externalizing symptom trajectories have been widely studied, their association with parental depressive symptom trajectories has yet to be explored.

We used data from a prospective birth cohort of 2,542 Czech children and their parents. Children reported internalizing and externalizing symptoms at ages 11, 15, and 18 years. Parental depressive symptoms were assessed eight times from the prenatal period to the child’s age of 11 years. Latent Class Growth Mixture Modeling identified parallel trajectories of children’s symptoms. Five parental depressive symptom trajectories were adopted from previous research.

We identified four distinct classes of children’s symptom trajectories: (1) low internalizing and low externalizing (64%), (2) low internalizing and high externalizing (8%), (3) elevated internalizing and elevated externalizing (19%), and (4) high internalizing and elevated externalizing symptoms (9%). Children were more likely to experience any symptoms if their mothers had elevated depressive symptoms. High maternal and paternal depressive symptoms were associated with high internalizing and elevated externalizing symptoms in children. Constantly depressed mothers with elevated depressive symptoms in fathers had a high likelihood of any symptom trajectories in children. Other strong predictors of children’s symptom trajectories included parental relationship status (e.g., divorce), prior abortion, as well as children’s sex, urban versus rural residence, stressful life events, and self-esteem.

Parents’ and children’s mental health trajectories are interconnected. Given the strong influence of parental relationship dynamics on both parental and child mental health, interventions should prioritize mitigating relationship strains to support family well-being.

Aims. Parental postpartum depressive symptoms have been extensively studied, but the combined longitudinal depression trajectories of parents and their long-term development beyond the postpartum period remain largely underexplored. We identified dyadic longitudinal depressive symptom trajectories in new parents, followed over an 11-year period, and compared parental characteristics, as well as child temperament and mental health factors, across different parental trajectory classes.

Methods. A prenatal cohort of 5,518 couples was studied. Depressive symptoms were measured using the Edinburgh Postnatal Depression Scale at eight time points: in the prenatal stage, in the newborn stage, and at 6 months, 18 months, 3 years, 5 years, 7 years and 11 years after the birth of the child.

Results. Dyadic Latent Class Growth Modelling identified five classes of couples: (1) mother has elevated depressive symptoms, father is non-depressed (24%); (2) both mother and father have elevated depressive symptoms (20%); (3) both mother and father are constantly non-depressed (42%); (4) both mother and father are constantly depressed (5%); and (5) mother is constantly depressed, father has elevated depressive symptoms (9%). Relationship maintenance (particularly being married or separated) was the most strongly associated with the classes. Socio-economic resources, emotional well-being, health, obstetric history and parental background also served as meaningful covariates. Child temperament and mental health showed weak correlations with parental trajectory classes.

Conclusions. Parents with postpartum depressive symptoms often experience depressive symptoms long-term. Separated parents are particularly vulnerable to adverse depressive trajectories. Our findings underscore the importance of dyadic methods in estimating unique combinations of parental depression trajectories.