Health Science Reviews

By Thompho Mathoni

Depression during pregnancy is more prevalent than often thought, impacting approximately 6-20% of pregnant women. Even mild depressive symptoms can affect a child’s brain development, especially in regions related to emotions and behaviour. Studies have found links between prenatal depression and changes in brain regions like the limbic system and prefrontal cortex, which play key roles in mood and affective behaviour.

Manning et al. reviewed and summarised the relationships between brain features and prenatal depression across 65 cross-sectional and longitudinal studies, offering a snapshot-in-time and an ongoing analysis of brain development after prenatal depression exposure.

Prenatal depression can influence a child’s brain development differently depending on the stage of development and the child’s age. These brain alterations often involve emotional regulation networks, including the amygdala, hippocampus and the frontal cortex, which continue to develop from early childhood through adolescence.

Interestingly, boys and girls may be impacted differently, with differential results especially observed during infancy. Males, for example,  exposed to prenatal depression, exhibited smaller amygdala and hippocampal volumes compared to females. These findings could explain the sex differences in behaviour and susceptibility to mental health issues. The impact of prenatal depression on the brain development of children can be seen in their mood, behaviour, and emotions as early as six months old, and these effects can last through adolescence and into adulthood.

While the exact mechanisms are still being explored, prenatal depression may influence the developing brain through several pathways, including hormones produced via the hypothalamic-pituitary-adrenal (HPA) axis, epigenetics, hypoxia, inflammation, and nutrition.

Preventing depression during pregnancy is a crucial aim for researchers. By recognising when and how the brain is most sensitive to change, they can better support mothers early on and give babies the healthiest start. These windows of opportunity are essential for shaping lifelong mental well-being.