An analysis of medical records data from three Massachusetts health care systems finds no evidence that prenatal exposure to antidepressants increases the risk for autism and related disorders or for attention-deficit hyperactivity disorder (ADHD). In their report being published online in Translational Psychiatry, the Massachusetts General Hospital (MGH)-based research team finds evidence that any increased incidence of autism or ADHD found in previous studies was probably associated with the severity of the mother's depression - a known risk factor for several neuropsychiatric disorders - and not from antidepressant exposure during pregnancy.
"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," says Roy Perlis, MD, MSc, MGH Department of Psychiatry, senior author of the current report and of an earlier study published in 2014. "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 2014 study, which was published in Molecular Psychiatry, analyzed electronic health record (EHR) data for children born at three Partners Healthcare System hospitals - MGH, Brigham and Women's Hospital and Newton-Wellesley Hospital. The current study also included EHR data from Boston Children's Hospital and from Beth Israel Deaconess Hospital, along with information from an additional group of children from the Partners EHR.
The researchers compared data on more than 1,200 children with an autism-related diagnostic code to that of more than 3,500 demographically matched control children with no neuropsychiatric diagnosis. As in the previous study, information regarding the children was paired with data from their mothers' EHRs, with specific attention to factors related to the mother's mental health. They also compared data on around 1,700 children with ADHD with that of a control group of nearly 3,800.
While the incidence of both autism and ADHD was increased in the children of women who had taken antidepressants prior to becoming pregnant, antidepressant exposure during pregnancy did not increase the incidence of either condition. Maternal psychotherapy, which like prepregnancy antidepressant use indicates more serious depression, did significantly increase the risk of either autism or ADHD, supporting the hypothesis that studies finding an increased incidence actually reflected the risk conferred by 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," says Perlis, an associate professor of Psychiatry at Harvard Medical School. "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."
Massachusetts General Hospital