Lebel C, Walton M, Letourneau N, Giesbrecht GF, Kaplan BJ, Dewey D. Prepartum
and Postpartum Maternal Depressive Symptoms Are Related to Children's Brain
Structure in Preschool. Biol Psychiatry. 2015 Dec 15. pii: S0006-3223(15)01039-2. doi: 10.1016/j.biopsych.2015.12.004. [Epub ahead of print]
Perinatal maternal depression is a serious health concern with potential lasting negative consequences for children. Prenatal depression is associated with altered brain gray matter in children, though relations between postpartum depression and children's brains and the role of white matter are unclear.
We studied 52 women who provided Edinburgh Postnatal Depression Scale (EPDS) scores during each trimester of pregnancy and at 3 months postpartum and their children who underwent magnetic resonance imaging at age 2.6 to 5.1 years. Associations between maternal depressive symptoms and magnetic resonance imaging measures of cortical thickness and white matter structure in the children were investigated.
Women's second trimester EPDS scores negatively correlated with children's cortical thickness in right inferior frontal and middle temporal regions and with radial and mean diffusivity in white matter emanating from the inferior frontal area. Cortical thickness, but not diffusivity, correlations survived correction for postpartum EPDS. Postpartum EPDS scores negatively correlated with children's right superior frontal cortical thickness and with diffusivity in white matter originating from that region, even after correcting for prenatal EPDS.
Higher maternal depressive symptoms prenatally and postpartum are associated with altered gray matter structure in children; the observed white matter correlations appear to be uniquely related to the postpartum period. The reduced thickness and diffusivity suggest premature brain development in children exposed to higher maternal perinatal depressive symptoms. These results highlight the importance of ensuring optimal women's mental health throughout the perinatal period, because maternal depressive symptoms appear to increase children's vulnerability to nonoptimal brain development.
"We found an association between brain structure in the kids and maternal depressive symptoms, so, while we cannot say the depressive symptoms cause this, there is definitely something different structurally in the brains of kids whose moms were more depressed," Dr Lebel said.
"We know that prenatal and postpartum depression in moms has negative consequences for kids in terms of things like behavior and learning, and in fact, the kids have higher risks of mental health problems themselves, so the brain structure is of interest because it can tell us a little bit about potential mechanisms, help us understand why maternal depression is associated with such outcomes in kids," she said…
They found that cortical thickness in two areas of the right hemisphere was negatively correlated with second trimester maternal depressive symptoms, after controlling for the child's age, sex, gestational age, and weight at birth, as well as maternal postsecondary education.
One region was located in the right inferior frontal area and included much of the pars opercularis and pars triangularis and small sections of the precentral and rostral middle frontal areas…
In addition, structural patterns in the children's white matter were different.
"These types of changes suggest to us that the children whose mums were more depressed have a more mature pattern of brain structure. Their gray matter was thinner, and we know that with age, gray matter becomes thinner. So it looks like the kids whose mums were more depressed have this premature pattern of brain structure, almost like their brains are developing too soon," said Dr Lebel.
"Brain development is obviously a complicated process, and there is very likely a narrow window for an optimal time for stages of development to occur. Our findings may indicate that with brains developing almost a little bit too soon, these children are losing flexibility and adaptability that other kids might have…
"Overall, in our society, roughly 1 in 5 people will meet diagnostic criteria for depression in their lifetime. The prevalence of depression in women, overall, is double that of men. Among women who are pregnant or have recently given birth, the rate of depression doubles to roughly four times the rate of depression in men. These statistics suggest that undiagnosed and untreated depression among pregnant women is very common and is a significant public health concern," he said…
A question raised by this study concerns whether treatment of depression with medications might have prevented these alterations in brain development, Dr Krystal noted.
"Only one of the 52 women in this study was treated with antidepressants. We recognize that some antidepressant medications, such as paroxetine or mood stabilizing medications, such as lithium, appear to carry some risk for developmental effects when taken during pregnancy," he said.
"This new study suggests that the risk of developmental impact of maternal antidepressant medications must be weighed against the potential developmental impact of ineffectively treated maternal depression for the offspring.
"There are many forms of treatment for mood disorders that carry limited developmental risk for babies, including psychotherapy, neurostimulation treatments, such as transcranial magnetic stimulation of electroconvulsive therapy, or antidepressant medications that have very little developmental impact," said Dr Krystal.