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Study suggests link between antidepressant exposure, autism

Autism was more common in children exposed to antidepressants during pregnancy, compared with children not exposed to antidepressants whose mothers had a history of psychiatric disorder.

“The fetal safety of antidepressant exposure during pregnancy has generated much debate after recent concerns of a possible association with autism in exposed offspring,” Dheeraj Rai, MBBS, MRC PSYCH, PhD, of University of Bristol, United Kingdom, and colleagues wrote. “In the past 5 years, several epidemiological studies have assessed the relation between antidepressant use during pregnancy and autism in offspring, but robust conclusions have been elusive. Although most studies found evidence of unadjusted associations, conclusions differed because of concerns about ‘confounding by indication.’”

To examine the association between maternal use of antidepressants during pregnancy and autism spectrum disorder (ASD) in offspring, researchers conducted an observational prospective cohort study of 254,610 individuals aged 4 to 17 years, of which 5,378 had autism. Study participants were born to mothers unexposed to antidepressants with no psychiatric disorder, mothers who received antidepressants during pregnancy, or mothers with psychiatric disorders unexposed to antidepressants during pregnancy.

There were 3,342 children exposed to antidepressants during pregnancy. Of these, 4.1% were diagnosed with autism, compared with 2.9% of children not exposed to antidepressants whose mothers had a history of psychiatric disorder (adjusted OR = 1.45; 95% CI, 1.13-1.85).

Propensity score analysis indicated comparable results, according to researchers.

Sibling control analysis indicated similar findings but with wider confidence intervals.

A negative control comparison found no evidence of any increased risk for autism in children with fathers prescribed antidepressants during maternal pregnancy (OR = 1.13; 95% CI, 0.68-1.88).

“This and other studies clearly suggest that there is an increased background risk of autism in children of women with psychiatric conditions, regardless of antidepressant treatment. Secondly, despite the observed relative risks, over 95% of women who took antidepressants during pregnancy did not have a child with autism. And, finally, if a causal link were robustly established, and if no pregnant women took antidepressants during pregnancy, only 2% of autism cases in this population would be prevented,” the researchers wrote. “On the other hand, given that this association might not solely be the byproduct of confounding by indication, it is important to continue investigation of possible underlying biological mechanisms that could help us to better understand the etiology of autism.” – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.