Study: Depression in an expectant mother doesn't harm her baby; anti-depressants do

• A new study examining the emotional health of expectant mothers has confirmed previous research showing that infants born to mothers who used anti-depressant drugs during pregnancy display altered brain function.
• The study also highlighted the negative impact of maternal anxiety on cognitive development in children. 
• Conversely, children born to mothers who had been depressed while pregnant later displayed superior problem-solving skills.
• More than 1 in 5 mothers enrolled in the study took anti-depressant medication during pregnancy.

A healthy baby in a healthy mother?

Given that the health of an expectant mother is known to be closely linked to perinatal outcomes and the later cognitive development of children, researchers in Canada and France conducted a study to examine the relationship in more detail. Specifically, they examined the effects of maternal anxiety and depression during pregnancy, as well as the use of anti-depressant drugs.

During pregnancy, depression and anxiety are the most common psychological conditions, with a prevalence of 20.7% for depressive and 18.2% anxious symptoms . . 

They based their study on data collected during the COVID period, expecting to find a deterioration in mental health given that “evidence suggests that the psychological well-being of pregnant persons often deteriorates during critical periods marked by stressful events.” In fact, they found that among the 472 mothers and children in the study, rates of depression were far higher than expected while anxiety rates were lower:

199 (42.2%) were exposed to symptoms of moderate to severe depression in utero, while 47 (10%) were exposed to moderate to severe symptoms of anxiety.

Distinguishing depression and anxiety

The researchers examined various areas of cognitive development in the 472 children: communication, fine motor, gross motor, problem-solving, and personal-social. Mothers were asked to complete a questionnaire at 18 months postpartum, providing information about the children’s health characteristics including head circumference, medication use, hospitalization history, COVID-19 infections since birth, and cognitive developmental outcomes.

To quantify the infants’ brain development, mothers were told to attempt the activities mentioned in the questionnaire with their child (such as getting up from a squatting position without support) and to record their child’s ability to comply (“yes,” “sometimes,” or “not yet”).

The study revealed that maternal anxiety was associated with weaker gross motor and communication skills in the 18-month-old baby. Maternal depression, by contrast, was associated with superior problem-solving skills. 

In this population-based cohort study, our findings suggest that after adjusting for potential confounders, children born during the COVID-19 pandemic exposed to moderate to severe symptoms of anxiety, in utero, seemed to require further assessment by a professional for the communication domain and to require learning activities that improve gross motricity. 

However, children exposed to in utero symptoms of depression seemed to have a lower risk of required learning activities and monitoring for the problem-solving domain.

Anti-depressants and cognitive damage

42.2 percent of mothers in the study experienced “moderate to severe depression.” Of them, around half took anti-depressant medication. The study found that this class of drugs had a negative impact on cognitive development:

In addition, those exposed, in utero, to antidepressants seemed to require learning activities and monitoring for fine motricity. 

The study also noted an increase in maternal depression during the “second wave of the pandemic” as compared to the first, which the researchers attributed to lockdowns and the “absence of available vaccines.”

20.8% of children in the study were exposed to antidepressants. While the researchers stated that, “evidence assessing the use of antidepressants before/during pregnancy and their impact on child development is still unclear,” there are in fact numerous studies showing the harms inflicted on a fetus by maternal use of anti-depressant drugs (see here, here, here, and here for examples).

The researchers concluded that while the links between maternal emotional health and the outcomes for their babies are clear, no one apparently knows why this should be:

The mechanism through which maternal mental health during the prenatal period affects child cognitive development remains unclear. Two studies suggest that high levels of maternal cortisol in plasma and its ability to cross the placenta to reach the fetus may play a role in the impact of maternal mental health in utero and child cognitive development.