Study calls into question link between prenatal antidepressant exposure and autism risk

http://www.eurekalert.org/pub_releases/2014-08/mgh-sci082614.php


26-Aug-2014

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Contact: Noah Brown
nbrown9@partners.org
617-643-3907
Massachusetts General Hospital
Study calls into question link between prenatal antidepressant exposure and autism risk
Previously reported autism risk appears to be attributable to mother's illness, not medication

Previous studies that have suggested an increased risk of autism among children of women who took antidepressants during pregnancy may actually reflect the known increased risk associated with severe maternal depression. In a study receiving advance online publication in Molecular Psychiatry, investigators from Massachusetts General Hospital (MGH) report that – while a diagnosis of autism spectrum disorder was more common in the children of mothers prescribed antidepressants during pregnancy than in those with no prenatal exposure – when the severity of the mother's depression was accounted for, that increased risk was no longer statistically significant. An increased risk for attention-deficit hyperactivity disorder (ADHD), however, persisted even after controlling for factors relating to a mother's mental health.

"We know that untreated depression can pose serious health risks to both a mother and child, so it's important that women being treated with antidepressants who become pregnant, or who are thinking about becoming pregnant, know that these medications will not increase their child's risk of autism," says Roy Perlis, MD, MSc, MGH Department of Psychiatry, senior author of the report.

The authors note that, while genetic factors are known to play a substantial role in autism, exactly how that risk may be exacerbated by environmental factors is not well understood. While animal studies and investigations based on health records have suggested an increased risk associated with prenatal antidepressant exposure, others found no such association. And since discontinuing antidepressant treatment significantly increases the risk of relapse – including an increased risk of postpartum depression – the current study was designed to clarify whether or not any increased autism risk could actually be attributed to the medication.

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While prenatal exposure to antidepressants did increase the risk for either condition, in the autism-focused comparison, adjusting for factors indicating more severe maternal depression reduced the strength of that association to an insignificant level. Taking antidepressants with stronger action in the serotonin pathway, which has been suspected of contributing to a possible autism risk, did not increase the incidence of the disorder. In addition, the children of mothers who took a serotonin-targeting non-antidepressant drug for severe morning sickness had no increased autism incidence. Prescriptions for antipsychotic drugs sometimes used to treat severe, treatment-resistant depression, as well as psychotic disorders, did appear to increase the risk for autism. For ADHD, however, the increased risk associated with prenatal antidepressant exposure remained significant, although reduced, even after adjustment for the severity of maternal depression.