Could prenatal depression therapy benefit babies’ brains?

Clinical takeaway: Offer evidence-based psychotherapy for prenatal depression; potential benefits for infant development add to its established maternal benefits, although long-term child outcomes remain unproven.

Prenatal depression affects an estimated 20% to 40% of pregnancies and has long been linked to adverse emotional and behavioral outcomes in children. Most prior evidence was observational, leaving uncertainty about whether treating maternal depression could directly influence infant neurodevelopment.

Researchers analyzed 109 infants born to participants in the CARE Project randomized trial, which previously showed that an 8-session interpersonal psychotherapy (IPT) program substantially reduced depressive symptoms and major depressive disorder during pregnancy compared with enhanced usual care. Infants underwent brain MRI at about 6 weeks of age and behavioral assessment at 6 months.

The primary finding was a difference in right hippocampal volume, a brain region involved in memory, stress responses, and emotional processing. Infants whose mothers received prenatal IPT had a significantly smaller right hippocampal volume than infants whose mothers received enhanced usual care, with an effect size corresponding to a moderate between-group difference. No significant differences were observed in the left hippocampus or either amygdala.

The structural findings appeared to have behavioral relevance. Smaller hippocampal volume in early infancy was associated with lower negative emotionality at 6 months, an early-life temperament trait linked to later mental health risk. The association was observed for both right and left hippocampal volumes, whereas amygdala volumes were not related to negative emotionality.

Investigators did not find evidence that infant sex modified the findings, and the hippocampal differences remained after accounting for factors such as birthweight, maternal health conditions, psychotropic medication use, and postnatal depressive symptoms.

“Our findings suggest that treating mothers’ depression during pregnancy may help shape a healthier developmental trajectory for the infant brain,” said corresponding author Elysia Davis, PhD.

Source: Demers CH, et al. (2026 Oct 16) Nat Commun. Infant Hippocampal and Amygdala Volume in an Observational Follow-up from a Randomized Clinical Trial for Maternal Prenatal Depression