New research suggests that prenatal exposure to antidepressants, primarily selective serotonin reuptake inhibitors (SSRIs), can significantly affect fetal brain development. The study, conducted by researchers at Columbia University Vagelos College of Physicians and Surgeons, concludes these changes could raise the risk of the offspring developing depression during puberty.

The study included 98 infants: 16 who were exposed to SSRIs in utero, 21 who were exposed to untreated maternal depression, and 61 healthy controls. The infants exposed to SSRIs in the womb displayed significantly increased volume in brain regions including the amygdala and insula, plus an increase in the connectivity between these regions.

"The amygdala and the insula play a critical role in emotional processing," says Jay Gingrich, one of the researchers working on the study. "We see these changes in mice after early-life SSRI exposure and have tied these changes to behavioral abnormalities that appear later in adolescence."

A study published in 2016 examining the health records of 15,000 subjects found those exposed to SSRIs in the womb displayed higher incidences of depression than those unexposed. The results showed that by the age of 15, a person was two to three times more likely to develop depression if they were exposed to SSRIs while gestating.

Despite the somewhat concerning results, these studies do have significant limitations. The most glaring issue is that it is somewhat difficult to fundamentally connect these results causally to SSRIs. Most of the subjects taking the antidepressants would have diagnosed medical or psychiatric problems, such as clinical depression or anxiety, making it hard to suggest the antidepressants are the primary cause for the anomalies in their offspring. Other research has also shown that amygdala volumes are different in the offspring of mothers with depression, regardless of antidepressant consumption, so it is difficult to specifically lay the blame at SSRIs.

In general, the use of antidepressants during pregnancy is considered relatively safe, and doctors do caution that the effects of major untreated depression during pregnancy has its own set of dangers. Jonathan Posner, another researcher working on this new study, suggests that non-SSRI antidepressants could be a good option.

"It's a difficult clinical decision," says Posner. "We know that maternal depression in and of itself can impact the health of the fetus and the relationship between mother and infant. So, doing nothing is not necessarily the answer. But other interventions, such as non-SSRI antidepressants and psychotherapy, can help depressed moms get through pregnancy."

Gingrich also adds that the team's mouse studies suggest timing matters when consuming SSRIs during pregnancy.

"There appears to be less risk in the first and second trimesters," he says. "So perhaps you could reduce the dose during the third trimester or switch to a non-SSRI antidepressant."

The research is just preliminary at this point, and the paper concludes by suggesting further work is needed to clarify the effects of SSRIs on fetal neurodevelopment.

The paper was published in the journal JAMA Pediatrics.

Source: Columbia University Irving Medical Center