Previous studies have observed that the children of depressed mothers are more likely to have delays in cognitive development, worse school performance, higher rates of behavioral problems, and deficits in social-emotional regulation.  Children of depressed mothers are also more likely to experience adolescent depression.  

Most studies have understood these vulnerabilities to neurodevelopmental problems and psychiatric illness in the context  of parental genetic contributions and/or the quality of parenting and the mother-child relationship.  However, there is a growing number of neuroimaging studies indicating that the fetal environment is vitally important and that risk may be transmitted from mother to child during fetal life.  These studies indicate that exposure to maternal depression in utero — independent of the medications we use to treat it — influences the development of the frontal cortex and the amygdala–prefrontal circuits, a finding that has implications for future affect regulation. Specifically, altered amygdala–prefrontal connectivity has been implicated in pediatric depression.

In a recent review (FULL TEXT available), Duan and colleagues review the findings of these studies.  Summarizing the findings of these studies, it appears that there are changes in connectivity between the amygdala and prefrontal cortex. Studies also suggest decreased hippocampal growth in the first six months of life, decreased cortical thickness, and, especially in female children, increased amygdala volume.  Several studies have demonstrated a dose response effect, such that higher levels of prenatal depressive symptoms were associated with more significant changes in the architecture of the infant’s brain.

While this type of research is still in its infancy, it provides us with another mechanism to explain the vulnerability to neurodevelopmental problems and psychiatric illness observed in the children of depressed mothers.  Putting these findings into practical clinical recommendations is not so easy.  We must consider the potential risks of exposure to medications during pregnancy, but at the same time take into account the effects of untreated psychiatric illness in the mother on the developing child.  Avoidance of all medications is not necessarily the safest option.  Women planning a pregnancy must be properly counseled regarding the risks of treatment versus the risks associated with untreated psychiatric illness in the mother, and the woman’s health care provider plays an important role in weighing these individual risks and selecting the best options for treatment.

Ruta Nonacs, MD PhD

 

 Duan C, Hare MM, Staring M, Deligiannidis KM. Examining the relationship between perinatal depression and neurodevelopment in infants and children through structural and functional neuroimaging research. Int Rev Psychiatry. 2019 May; 31(3): 264-279. Free article.