Treating depression in pregnancy linked to differences in infant brain development

A study suggests interpersonal psychotherapy during pregnancy may influence babies’ hippocampal development and later emotionality, though the findings do not prove a direct causal link.

Treating depression during pregnancy with interpersonal psychotherapy may do more than improve a mother’s mood: it may also influence how an infant’s brain develops, according to a study published in Nature Medicine.

Researchers led by Catherine H. Demers of the University of Colorado Anschutz Medical Campus followed 109 infants born to mothers who had taken part in a randomised trial of psychotherapy during pregnancy. The study looked at early brain measures at six weeks, including the hippocampus and amygdala, as well as negative emotionality at six months, a marker of fussiness, distress and difficulty settling.

The findings suggested that babies born to mothers who received interpersonal psychotherapy had a smaller right hippocampus than those whose mothers received enhanced usual care. The left hippocampus and amygdala did not show a significant difference between the groups. The research team also found that a smaller hippocampal volume was linked with lower negative emotionality later in infancy, a result that points to a possible connection between prenatal treatment and early emotional regulation.

Psychiatric News reported that the right hippocampus difference was about 5%, while the study’s authors said the pattern supports the idea that pregnancy may be a critical period for intervention. Elysia Poggi Davis of the University of Denver said in a statement that treating a mother’s depression during pregnancy “may help shape a healthier developmental trajectory for the infant brain” and that supporting maternal mental health is also an investment in child health.

The findings add to a wider body of research showing that interpersonal psychotherapy can ease depression and anxiety during the perinatal period, according to a previous systematic review published in the Journal of Affective Disorders. Taken together, the evidence suggests that mental health care in pregnancy may have benefits that extend beyond the mother, although the latest study was observational in its follow-up phase and does not prove a direct cause-and-effect relationship.