Autism Risk with Prenatal Antidepressant Use Insignificant After Controlling for Major Maternal Depression

Autism risk shown not to increase in children exposed to antidepressants in utero when researchers accounted for depression severity.

The increased risk of an autism spectrum disorder diagnosis in children whose mothers took antidepressants while pregnant was not statistically significant when the severity of the mother’s depression is accounted for, new research suggests.

An increased risk for an attention-deficit/hyperactivity disorder (ADHD) remained, however, even after researchers accounted for factors related to maternal 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,” said Roy Perlis, MD, of Massachusetts General Hospital’s department of psychiatry and the study’s senior author, in a press release.

The research was published online on August 26, 2014, in Molecular Psychiatry, and aimed to clarify whether any increased autism risk could be tied to antidepressants. Genetic factors are known to play a role in autism, and might be exacerbated by environmental factors. Although animal studies and investigations suggest an increased risk with prenatal antidepressant exposure, other studies found no association.

Researchers analyzed electronic health record data for children born at 3 Massachusetts hospitals between 1997 and 2010. Researchers pinpointed the diagnostic code for the category that includes autism, and matched 1400 participants with autism to 4000 controls without an autism diagnosis. Participants were matched for birth year as well as several demographic factors. Researchers then paired the children’s information with the information of their mothers, and noted factors related to diagnosis and treatment of major depression or other mental illness, including antidepressant or other psychotropic drug prescriptions.

Researchers conducted a similar analysis for 2250 participants who received an ADHD diagnosis and 5600 matched controls.

Although the risk for either condition increased with prenatal antidepressant exposure, adjusting for factors indicating more severe depression reduced the strength of the autism risk association to an insignificant amount. This suggests that the risk of autism observed with prenatal exposure to antidepressants in previous studies may have been confounded by the severity of maternal depression, according to the researchers.

Taking antidepressants with stronger action in the serotonin pathway did not increase the autism incidence, researchers noted. They also found no increased autism risk in participants whose mothers took antidepressants for morning sickness.

Despite this, antipsychotic drugs used to treat severe or treatment-resistant depression, did appear to increase autism risk, researchers said. The risk for ADHD remained significant, as well, although it too was reduced after adjusting for depression severity.

Discontinuing antidepressant risk significantly increases the risk of relapse, including the risk of developing postpartum depression, the researchers noted.

“There are a range of options—medication and non-medication—for treating depression and anxiety in pregnancy,” Dr. Perlis said. “But if antidepressants are needed, I hope parents can feel reassured about their safety.”