Can Treating Prenatal Depression Affect the Baby’s Brain?

Depression is one of the most common and serious complications of childbirth. Maternal depression can happen anytime during the perinatal period – the timeframe throughout pregnancy and the first year postpartum. Research suggests that approximately 16% of pregnant people experience depression, and roughly one third of women presenting with maternal depression in the postpartum period actually had symptom onset during pregnancy.

Depression during pregnancy can have serious health consequences for both the mother and infant. Prenatal depression has been associated with worse birth outcomes, mother-infant bonding, quality of life and relationships, and children’s development.

Researchers are increasingly interested in understanding whether prenatal depression treatments for expectant moms might also have implications for infant development. A new study published in Nature Communications explored this question by investigating whether treating depression during pregnancy was associated with differences in infant brain development and later emotional behavior.

What did the researchers study?

Researchers followed 109 infants whose mothers had participated in a clinical trial examining treatment for depression during pregnancy. Participants were randomly assigned to two groups.

One group received eight, 50-minute sessions of interpersonal psychotherapy (IPT). IPT is an evidence-based treatment for depression and anxiety that focuses on how relationships and life changes affect mental health. This approach is particularly well-suited to the perinatal period because of the significant role transitions, relationship conflicts, and grief or loss that are often associated with new parenthood. IPT also addresses interpersonal difficulties, including limited social support and relationship conflict, which are associated with perinatal depression and anxiety. IPT aims to improve mental health by helping expectant parents navigate these relational challenges and strengthen their support systems.

Due to researchers’ knowledge of participants’ depressive symptoms, there wasn't a standard control group that received no treatment whatsoever; instead, the comparison group received enhanced usual care (EUC). EUC included one hour of depression education, mental health resources, and ongoing monitoring.

What did researchers find?

Mothers who received interpersonal psychotherapy (IPT) experienced greater reductions in depression symptoms during pregnancy than those who received enhanced usual care (EUC). Depression symptom scores decreased by 47% on the Symptom Checklist and 52.5% on the Edinburgh Postnatal Depression Scale (EPDS) among those receiving IPT, compared with reductions of 13% and 32.3%, respectively, in the EUC group. IPT was also associated with higher rates of remission from depression.

Researchers then examined whether prenatal depression treatment was associated with differences in infant brain development. When the infants were six weeks old, researchers used magnetic resonance imaging (MRI) to measure two brain regions: the hippocampus, which supports learning and memory, and the amygdala, which is involved in emotional processing. Then, at six months, researchers assessed infants' negative emotionality, which refers to an infant’s expression of distress or negative emotional responses when confronted with an unfamiliar or potentially unsettling stimulus.

At approximately six weeks of age, infants of mothers who received IPT treatment had significantly smaller right hippocampal volume compared to infants of mothers who received EUC.

Researchers examined whether infant brain volume at six weeks of age was associated with infants’ emotionality at six months, as assessed through behavioral observation. The researchers found that smaller hippocampal volumes were associated with lower subsequent infant negative emotionality.

Study findings provide initial evidence that there may be a relationship between prenatal depression treatment, early brain development, and infant emotional behavior. However, the study did not establish that maternal intervention during pregnancy caused improvements in infant development. The researchers emphasized that more work is needed to understand the biological processes underlying these findings and whether the observed differences have lasting developmental significance.

Why does this matter?

Much of the existing research has examined associations between maternal depression and children's development. This study offers a different perspective by exploring whether an intervention for depression during pregnancy may also be associated with differences in infant brain structure. In an interview, one of the study's researchers stated, "Our findings suggest that treating a mother’s depression during pregnancy may help shape a healthier developmental trajectory for the infant brain…This study highlights pregnancy as a critical window for intervention and reinforces that supporting maternal mental health is also an investment in child health."

This study reinforces that depression during pregnancy deserves attention and effective treatment. Expectant parents should not wait until after childbirth to seek support for their mental health. Instead, treating depression is valuable for the pregnant person's well-being in its own right and may also have positive effects on infant development.

Ultimately, the takeaway is not that maternal therapy during pregnancy has been proven to improve a baby's brain development. Rather, treating prenatal depression is important for the parent's well-being, and researchers are beginning to understand how that care may also relate to early infant development.

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