Environmental variables influence the relationship between maternal depressive symptoms and toddlers' neurocognitive and affective outcomes.

Motherhood is often associated with joy, but it can pose significant challenges, and in some instances lead to perinatal mental health problems. Maternal depressive symptoms can hinder a mother's ability to attune to her infant's needs, potentially affecting caregiving quality and emotional support. This study examines how parenting style and a cognitively stimulating home environment (i.e., individual level) and relative social deprivation (i.e., area level) contribute to the relationship between maternal depressive symptoms and offspring's neurocognitive and affective outcomes at 18 months. Participants were 479 mothers and children recruited as part of the Developing Human Connectome Project. Maternal postnatal depressive symptoms were assessed at term with the Edinburgh Postnatal Depression Scale. At a median corrected age of 18.4 months (range 17.3-24.3) children's outcomes were evaluated with the Bayley Scales of Infant and Toddler Development, Third Edition, the parent-rated Child Behaviour Checklist 1½ - 5 and the Early Childhood Behaviour Questionnaire. The Parenting Scale measured dysfunctional parenting in discipline situations; the Cognitively Stimulating Parenting Scale assessed experiences promoting cognitive stimulation in the home. Family socioeconomic status was evaluated using the Index of Multiple Deprivation. Toddler's outcomes were summarised into latent dimensions labelled 'neurocognitive' and 'affective'. Results from bootstrapped-based mediation analysis showed that a permissive parenting style and a less cognitively stimulating home environment modified the relationship between depressive symptoms and toddlers' neurocognitive outcomes. However, other factors, such as relative social deprivation and parental over-reactivity, did not alter this. Results also showed that an over-reactive parenting style modified the relationship between maternal depressive symptoms and toddlers' reduced capacity for effective emotional regulation, while relative social deprivation, permissive parenting and a cognitively stimulating home environment did not. These findings highlight the importance of understanding how environmental factors interact with parenting styles, and influence child development. The study emphasizes the need for interventions that create stable and supportive environments, mitigating the impact of suboptimal parenting on children's developmental outcomes.