Examining pathways between trajectories of maternal depressive symptoms, harsh parenting, and adolescent executive functions: insights from the 2004 Pelotas birth cohort.

Continuous exposure to maternal depressive symptoms throughout childhood has been consistently linked to poorer executive functions in offspring. However, the mechanisms underlying this association remain understudied, particularly with respect to long-term effects in adolescence. This study aimed to test whether harsh parenting mediates the effect of maternal depressive trajectories on executive functions. Data were drawn from 1,949 participants of the 2004 Pelotas Birth Cohort. Maternal depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale from 3 months to 11 years. Harsh parenting was measured using the Parent-Child Conflict Tactics Scale at 11 years. Executive functions were evaluated at 15 years using the Cambridge Automated Neuropsychological Test Battery. Path analyses were conducted using structural equation modeling. 75% of the mothers belonged to the "moderate-low" or "low" depressive symptom trajectories, while 10.8% were in the "decreasing", 9.0% in the "increasing", and 5.2% in the "chronic-high" trajectories. Mothers with severe and persistent depressive symptoms displayed more harsh parenting behaviors (β(SE) = 0.218(0.030), 95%CI [0.160, 0.277]), which, in turn, were linked to poorer adolescents' sustained attention (β(SE)=-0.093(0.022), 95%CI [-0.137, -0.049]). Adolescents whose mothers belonged to either the high-chronic or decreasing trajectories exhibited poorer sustained attention and episodic memory through harsh parenting, suggesting that early exposure to maternal depressive symptoms may have lasting consequences on cognitive development. Maternal depressive symptoms impact adolescents' executive functions through harsh parenting. Interventions addressing maternal mental health and parenting, especially in early childhood, may foster healthier cognitive development.