It’s standard for doctors to tell pregnant women that to take care of their unborn children, they must take proper care of themselves. However, new evidence showing an association between selective serotonin inhibitors (SSRI) use during pregnancy and having a child with autism may complicate that seemingly straightforward advice for women who suffer from depression.
Published this week in Pediatrics, the study examined whether prenatal exposure to SSRI medicines—which are commonly used to treat depression, anxiety, and other mental health disorders—increased an infant's chance of having autism spectrum disorders.
Of 966 mother-child pairs, boys with autism were three times as likely to have been exposed in vitro to SRRI as typically developing boys. The vast majority of the study’s participants were boys, so it was harder to determine whether there was an elevated risk for girls. However, the study did find that boys with developmental delays were also more likely to have had prenatal exposure to SSRI, and first-trimester exposure posed the greatest risk.
Despite this documented link, now is not the time for women who take SSRIs to panic and ditch their medicine. Whenever there is a new study connecting autism to some external factor ingested during pregnancy, the gut reaction of prospective mothers is to cut said factor out completely. “These kinds of things sound scary. They think 'Oh, there’s been some inkling, and read it as bottom line of don’t take serotonin during pregnancy,” says Dr. Melissa Nishawala, and assistant professor at NYU Langone’s Child Study Center.
But while pregnant women may completely excise tuna, microwaveable meals, and other products shown to have even the slightest association with autism, depression medication cannot—and shouldn’t be—disposed of so swiftly.
For one, there may be a distinct underlying explanation for the link between SSRIs and autism: depression. The evidence does not prove that infants exposed to SSRIs that develop autism do so because of that prenatal exposure. Dr. Andrew W. Zimmerman of Massachusetts General Hospital is one of the lead authors of the study. He says it is quite possible that the elevated likelihood of autism in children of mothers who take SSRIs could be masking for an association between maternal depression and autism.
“I think we pointed out in the study that we don’t [know] the relationship itself between depression and autism,” he explains. “Presumably, SSRIs are taken because women need them. The big unknown is: If those women weren’t taking SSRIs, would their children have autism? We just don’t know that. It’s possible depression in the mother may be one of the precursors for autism itself.”
Researchers have known for some time that serotonin is critical for the early fetal development of the brain, and that the brains of people with autism are often deficient in the neurotransmitter. “This study shows an association between the use of SSRIs and autism spectrum disorders,” says Dr. Ariela Frieder of Montefiore Medical Center in New York. “However, association does not mean causation, and this is very important for the woman to understand.” It is also important to contextualize how many cases of autism could be accounted for if a causal link to SSRI proved true. Based on the cases in the study, Nishawala says, SSRI exposure “would account less than a percentage fraction of kids with autism.”
There may be a distinct underlying explanation for the link between SSRIs and autism: depression.
Even if we put all of these concerns aside and an absolute causal relationship between SSRIs and autism is discovered, there would still be significant risks in pregnant women going off of their medicines. “I think a lot of women think about the risk of their medicines to their babies, but they don't think about the risk of being depressed during a pregnancy,” says Dr. Frieder.
Untreated depression may have its own negative ramifications. For women, “there are risks in regards to bonding and attachment. Women may not want to deal with or touch the baby. For some women, they feel so needy and worthless that they don’t feel they can take care of the baby,” explains Frieder. As for the babies, says Frieder, “Some can having feeding problems. They can be more irritable and colicky. They can have mental illnesses.”
Not a single doctor interviewed for this article believed women should necessarily stop taking SSRIs during pregnancy, including those doctors who worked on the study. “My opinion is not for women to stop taking SSRIs, but to review whether they need to be taking them,” says Zimmerman. “I know of women taking SSRIs for just mild depression. On the other hand, there are women with very serious cases of depression.”
Nishawala says the study “does not give me a strong sense of pause towards prescribing SSRIs.” Returning to the original basic advice to pregnant women to stay as healthy—mentally and physically—as possible, she says, “I wouldn’t want women struggling with depression to think this is a reason not to take antidepressants. When there’s severe depression—even moderate—that doesn’t respond to psychotherapy, then medication is need, and I would hope people feel it’s an option.”