Treating depression during pregnancy may have positive influences on baby brain development and lead to healthier emotional development during infancy, according to new research published in Nature Communications .

Prenatal depression is surprisingly common, affecting an estimated 10% of pregnant individuals according to the American College of Obstetricians & Gynecologists. Previous research has linked depression during pregnancy with an increased risk of emotional, behavioral and mental health challenges in children. However, much of that evidence has been observational, making it difficult to determine whether treating depression during pregnancy could change developmental outcomes.

The study included a randomized, controlled trial where over 200 pregnant participants with depression were assigned to receive personal psychotherapy, or enhanced normal care. Those who were randomized to psychotherapy received eight weekly 50 minute sessions of therapy which focused on relationships and social support. People in the comparison group received normal obstetric care, an educational session about prenatal depression and information about community mental health services.

Researchers found that infants whose mothers received the psychotherapy during pregnancy showed differences in the development of the hippocampus, a brain region involved in memory and emotion. The hippocampus differed by 5% between infants in the psychotherapy and normal care groups.

The researchers also found that differences in this brain region were associated with better emotion regulation at 6 months of age. Infants whose mothers received psychotherapy showed lower negative emotionality, suggesting that treating depression during pregnancy may influence early emotional development.

The findings build on previous research linking maternal depression with children’s emotional and behavioral outcomes.

“Research has long shown that depression during pregnancy is associated with differences in children’s emotional and behavioral outcomes, but most of that evidence has been correlational,” said Catherine Demers, PhD, assistant professor of psychiatry at the University of Colorado Anschutz and lead author of the work. “By using a randomized clinical trial, we were able to test whether treating depression during pregnancy can actually influence early brain development in infants.”

However, the study’s findings do not establish whether these differences persist beyond infancy or affect children’s longer-term mental health. The researchers stress that further studies will be needed to understand the lasting implications of the observed brain differences.

“Our findings suggest that treating mother’s depression during pregnancy may help shape a healthier developmental trajectory for the infant brain," said Elysia Davis, PhD, professor of psychology at the University of Denver and the SEED Research Institute and senior author of the work.

Given the prevalence of prenatal depression and the availability of treatments, improving access to mental health care during pregnancy may represent an important opportunity to support healthy early development.

“This study highlights pregnancy as a critical window for intervention and reinforces that supporting maternal mental health is also an investment in child health,” said Dr Davis.