Study Finds No Link Between Prenatal Antidepressant Use and Autism
Previous studies finding a link between antidepressants and autism may have actually been finding a link between autism and maternal depression itself.
An analysis of medical records data from three Massachusetts health care systems found no evidence that prenatal exposure to antidepressants increases the risk of autism, related disorders, or attention deficit/hyperactivity disorder (ADHD), according to research published in Translational Psychiatry.
Instead, the research team found evidence that any increased incidence of autism or ADHD from previous studies was most likely associated with the mother's severity of depression, and not from antidepressant exposure. Severe depression is a known risk factor for several neuropsychiatric disorders.
"The fact that we now have found, in two large case-control studies, no increase in the risk for autism with antidepressant use itself should be very reassuring," said Roy Perlis, MD, Massachusetts General Hospital (MGH) Department of Psychiatry, in a statement. "Some of the studies that have suggested an association did not account for key differences between mothers who take antidepressants and those who don't, in particular that those taking antidepressants are more likely to have more severe illness."
The previous study in which no association between prenatal antidepressants and autism was found was published in 2014 in Molecular Psychiatry, and analyzed electronic health records (EHR) for children born at MGH, Brigham and Women's Hospital, and Newton-Wellesley Hospital. The current study also included data from these hospitals as well as data from Boston Children's Hospital, Beth Israel Deaconess Hospital, and information from the Partners EHR.
For this study, the researchers compared data on more than 1200 children with an autism-related diagnostic code with more than 3500 control children with no neuropsychiatric diagnosis, and compared 1700 children with ADHD with a control group of almost 3800 children. The children's information was paired with their mothers' EHRs, focusing on the mothers' mental health.
The researchers found that while both autism and ADHD were more common in the children of women who had taken antidepressants before becoming pregnant, the incidence of autism and ADHD was not higher in women who took antidepressants while pregnant.
However, in women who had psychotherapy, indicating more serious depression, the incidence of autism and ADHD was significantly higher in their children, supporting the hypothesis that previous studies finding a link between antidepressants and autism may have actually been finding a link between autism and maternal depression itself.
"While taking any medicine during pregnancy can be a difficult decision, we hope the results of our two papers — which now cover more than 2,500 children with autism and almost 4,000 with ADHD — will provide some reassurance to women concerned about getting treatment for depression or anxiety during pregnancy," said Dr Perlis in a statement. "While there are depression treatments that don't involve medication, for some patients they are not effective, available or preferred. We want women and the clinicians working with them to be as informed as possible when making this decision."
Castro VM, Kong SW, Clements CC, et al. Absence of evidence for increase in risk for autism or attention-deficit hyperactivity disorder following antidepressant exposure during pregnancy: a replication study. Transl Psychiatry. 2016; doi:10.1038/tp.2015.190.