A recent study suggests that prenatal exposure to antidepressants affects the risk of developing attention deficit-hyperactivity disorder (ADHD), but not autism spectrum disorder (ASD). Results of the study were published on August 26, 2014 in Molecular Psychiatry. Previous studies have observed a risk of autism with maternal use of antidepressants during pregnancy. This current study suggests the increased risk previously observed may have more to do with maternal illness (depression) rather than antidepressant exposure.
About 1 in 68 children are affected by ASD. Although much of the risk for autism is inherited (genetic variability explains around 70% of autism cases), environmental factors also contribute. And since more and more people are being diagnosed with ASD, there has been an increased effort to identify potentially modifiable risks (i.e., risk factors that can be controlled or modified). In recognition of the growing population of persons with ASD, Connecticut established the Division of Autism Services. The Division provides a range of services to children and adults with ASD and their families.
The current study analyzed associations between prenatal antidepressant exposures and ASD or ADHD risk in children. The researchers found that antidepressant exposure during pregnancy was associated with ASD risk. However, the severity of maternal mental illness also affected this risk. Moreover, the association of antidepressant exposure was no longer significant when taking into account the mother’s history of major depression. Conversely, the rate of ADHD was slightly increased in children exposed to antidepressants prenatally, even after adjusting for the severity of maternal depression. Environmental factors are considered more important in ADHD than ASD because besides affecting the expression of ADHD, environmental factors affect the threshold of diagnosis of ADHD (for example, the controversy in the United States where the prevalence of ADHD varies by state because of the laws over school entrance and other educational policies).
Overall, the results suggest that the risk of autism that has previously been observed with prenatal antidepressant exposure may be better explained by risk associated with maternal illness. The findings do indicate that prenatal antidepressant exposure may be modestly associated with ADHD risk. Maternal depression during pregnancy is associated with health complications for both the mother and child. Failing to treat depression in pregnancy can be very dangerous. “From the child’s perspective, it is likely that the potential harm caused by any increased risk of ADHD or autism would be much less than the potential harm of having a mother suffering from depression,” said Dr. Celso Arango, Scientific Director of the Spanish Centre for Biomedical Research in Mental Health, Madrid. Additional studies are needed to more precisely estimate the effects of antidepressants on ADHD risk, if any.