Antidepressants in Pregnancy Linked to Autism

A new study linking antidepressant use in pregnancy with an increased risk of autism presents another challenge for pregnant women suffering from depression.

Antidepressants in Pregnancy Linked to Autism OndroM/Shutterstock

For women dealing with depression during pregnancy, deciding how to treat their condition can be difficult. Expectant mothers need to take care of themselves, but also don't want to do anything to harm their babies. The mixed research on the effects of antidepressants doesn't make that decision any easier. Recent studies have had good news for pregnant moms taking antidepressants—but now, a new study published in JAMA Pediatrics shows that pregnant women's use of antidepressants raises the risk of autism in children.

Are antidepressants safe?

The researchers studied over 145,456 children, comparing which moms took antidepressants during pregnancy and which children were diagnosed with autism. "Using antidepressants during the second and third trimesters of pregnancy increases the risk of having a child with autism—an 87 percent increased risk with any antidepressants, and more than double the risk with SSRI use [a group of drugs called selective serotonin reuptake inhibitors] specifically," study author Anick Berard, Ph.D., a professor in the University of Montreal's Faculty of Pharmacy and its affiliated CHU Sainte-Justine children's hospital, tells Fit Pregnancy. "This is above and beyond the risk associated with maternal depression, which was a 20 percent increased risk in our study."

Although we usually think the biggest dangers to a developing baby are in the first trimester, "the second and third trimesters are critical for brain development," Berard says. So the study's finding "makes biological sense," because the chemical serotonin is essential for brain cell development, and its blockage by SSRIs could disrupt healthy growth. "We don't know the real causes of autism," she says. "There is probably a strong genetic factor but also environmental factors. We have looked at one: in-utero antidepressant exposure."

More research showing risk

This is the latest in several studies on the topic, with all reporting a raised risk of autism with antidepressants. "Our study is the largest and most comprehensive thus far," Berard says. This study is also the first to break down antidepressants by type, and in doing so discovered the specific risks of SSRIs, which include Zoloft and Prozac. Because random trials on pregnant women aren't ethical, scientists have to rely on observational studies like this one. But as the growing body of research comes to the same conclusion, "accumulation of such findings will lead to causation," Berard says. Could the rise in prescription antidepressants explain the rise in autism? "In part, yes, given the association we have seen in our study," she says, noting that more detection and a wider definition are also reasons for it.

Although the study didn't measure the severity of each woman's depression, they found that expectant moms who took more than one type of antidepressants (probably indicating severe depression) were more than four times as likely to have a child with autism. In terms of what dosage poses the most risk, Berard says that's her next area of research. "Our findings are for at least one dose of antidepressant—use vs. non-use—during late pregnancy," she says of the current study. "Now, we will look at whether there is a dose-response effect in a later study."

Should you stop your meds?

So, what should women with depression do to treat their condition during pregnancy? "This study is not advocating untreated depression," Berard says. "However, it is certainly advocating treatment of depression with something other than antidepressants during pregnancy." Other treatment options like exercise and psychotherapy have been shown to effectively treat mild to moderate depression, which makes up 80 to 85 percent of the cases in pregnant women, she says.

But drugs are widely prescribed in part because many doctors and patients alike believe that depression can only be treated with medication, "which is false," Berard says. Plus, women's pre-pregnancy dose might not even be effective after conception. "Because of increased metabolism caused by the pregnancy itself, a woman on antidepressants would need to increase her dosage during pregnancy if she wants to have the same benefits," Berard says. "In fact, this is never done. Either women discontinue or remain on the same dosage, [in which case] the benefits are almost null. In this situation, the risks outweigh the benefits."

The study's results are likely to alarm the 6 to 10 percent of pregnant women taking antidepressants, but Berard says that's not her intention—rather, she wants women to have all the information in order to make the best choice. "Our study is not to scare women," she says. "Women can make informed decisions but they need to have evidence-based data. A discussion with their physician is warranted in order to fully consider all the treatment options."