Many women trying to get pregnant rejoice when they see the blue plus sign on the pregnancy test. However, for women with depression, the happiness doesn't always set in; instead it's fear of how antidepressants will affect their baby's health. A study published in the Journal of the American Medical Association hopes to provide some solace for expectant mothers with depression: antidepressant use during pregnancy does not cause autism, or ADHD.

"To our knowledge, this is one of the strongest studies to show that exposure to antidepressants during early pregnancy is not associated with autism, ADHD or poor fetal growth when taking into account the factors that lead to medication use in the first place," said Brian D'Onofrio, lead author of the study, and professor at Indiana University Bloomington College of Arts and Sciences' Department of Psychological and Brain Sciences, in a statement.

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Previous research has been on both sides of the fence when it comes to the antidepressant and autism debate.

For example, a study in JAMA Pediatrics found boys with autism were three times more likely to have been exposed to antidepressants, or SSRIs in the womb, than those without a diagnosis. Moreover, the study also found boys exposed to drugs including Celexa, Lexapro, Paxil, Prozac and Zoloft during pregnancy were more likely to have developmental delays. Yet, the researchers only found an association, not a cause-and-effect between prenatal exposure of SSRI antidepressants and autism risk in boys.

In contrast, a study in the New England Journal of Medicine found the opposite to be true: antidepressant use during pregnancy is not associated with an increased risk of autism. The researchers looked at the same type of SSRIs as the study above, yet came to a different conclusion. This is mainly due to the JAMA Pediatrics study only looking at children who were evaluated for autism, with a confirmed diagnosis by a psychiatrist or neurologist.

Moreover, these researchers only looked at mothers who took antidepressants before getting pregnant, during the first trimester, and during the second and third trimesters, without reporting findings for the second trimester alone, or the third trimester alone. In other words, reporting the results for each trimester individually means their study would've had less significant numbers when it came to SSRIs during pregnancy and autism risk. The researchers divided the data in several ways, so it may appear there’s an increase in autism when taking antidepressants.

In an effort to dismantle the lingering uncertainty between antidepressants and autism, D'Onofrio and his colleagues sought to analyze data on over 1.5 million children whose mothers took antidepressants during pregnancy. The researchers also took into account how maternal depression, genetic, and environmental factors could influence autism risk. The study was divided into two segments: to determine if the association between antidepressants and autism can be explained by comparing siblings, and time of exposure.

First, siblings who were born after their mothers used antidepressants while pregnant were compared to those born when their mother didn't use the drugs. Autism rates were not all different among brothers and sisters, according to the researchers. Antidepressants were not found to be the main cause of autism, but rather genetic or environmental factors were more likely to influence the effect the mother's depression had on their development.

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For example, a genetic overlap exists in people who have depression and people who have autism. In addition, those who have a family history of depression can also have an increased risk of autism. This stresses the importance of researchers taking into account other factors that may influence the disorder.

"The ability to compare siblings who were differentially exposed to antidepressants in pregnancy is a major strength of this study," said D'Onofrio.

The researchers also compared children born to mothers who used antidepressants before pregnancy, but not during pregnancy, to those whose mothers began to use meds during pregnancy. Fathers' use of antidepressants was also looked at to determine if genetic factors were more likely to cause autism. Here, when looked at as a whole, these uses were associated with an increased risk for autism, ADHD, and poor fetal growth, but this shows it's genetics and environmental factors that influence these outcomes — not antidepressant use during pregnancy.

When all the other factors were accounted for, the association was no longer strong. Therefore, the link between antidepressants and autism is not due to exposure to antidepressants during pregnancy, but to other factors, researchers said. 

"The additional comparisons provide further evidence that other factors -- not first-trimester exposure to antidepressants -- explain why women who took these medications during early pregnancy were more likely to have offspring with these pregnancy and neurodevelopmental problems," D'Onofrio said.

These findings help reassure mothers struggling with depression that antidepressants do not directly raise autism risk. Women battling depression during pregnancy can often carry the burden that they did something wrong, hence why their child has autism. However, science shows the association between these drugs and autism is significantly low.

Women should continue to take their antidepressants when pregnant, and consult their doctor for further counseling to control other relevant autism risk factors.

Source:Sujan AC, Rickert ME, Oberg AS et al. Associations of Maternal Antidepressant Use During the First Trimester of Pregnancy With Preterm Birth, Small for Gestational Age, Autism Spectrum Disorder, and Attention-Deficit/Hyperactivity Disorder in Offspring. JAMA. 2017.

See Also:

An 'Aspie' Tells What It's Like To Live With Asperger's, Autism Spectrum Disorder

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