Studies find no evidence for autism link to antidepressant use

April 18, 2017 8 AM PT

One day after a study questioned the putative link between autism and maternal use of antidepressants, two more studies provide more definitive evidence suggesting there is no causal link.

The studies examined data on mothers and children with autism spectrum disorder in Sweden and Ontario, Canada. They were published Tuesday in JAMA, the Journal of the American Medical Association,

-- The study with Swedish data found no increased risk of ASD, ADHD or low birth weight in offspring of mothers who took antidepressants during the first term. There was a small increased risk of preterm birth. It can be found at j.mp/indswe.

The study examined records from more than 1.5 million births, making it an exceptionally large study of the effects of antidepressant use during pregnancy.

-- In the study with Ontario data, no association was found between children with ASD and the use of SSRI antidepressants during pregnancy among mothers receiving public drug coverage.

“Although a causal relationship cannot be ruled out, the previously observed association may be explained by other factors,” the study stated.

The earlier study, published Monday in JAMA Pediatrics, found evidence suggesting that the link between antidepressant use and ASD children may be a confounding effect — mothers with psychiatric disorders are more likely to take antidepressants. The underlying disorder, not the antidepressants, could well be a contributing cause, the study said.

That study said earlier media coverage had exaggerated the evidence for a link, which could potentially cause mothers to stop taking antidepressants during pregnancy. This could have disastrous consequences, including maternal suicide, the study said.

The study of Swedish mothers and children controlled for confounders by taking into account the mother’s age at birth and the status of siblings whose mothers used antidepressants during one pregnancy but not another.

“The ability to compare siblings who were differentially exposed to antidepressants in pregnancy is a major strength of this study,” said study leader Brian D’Onofrio, in a statement. D’Onofrio is a professor in the IU Bloomington College of Arts and Sciences’ Department of Psychological and Brain Sciences.

In an accompanying JAMA editorial, Dr. Tim F. Oberlander said more attention needs to be focused on the children, regardless of the origin of their ASD.

“Regardless of whether associations between antidepressant use during pregnancy and autism spectrum disorder reflect drug effects or risks inherent to maternal mental health, efforts should focus on how best to promote optimal child health in ways that harness a child’s inherent developmental plasticity,” Oberlander said.

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