Antidepressants may Influence Risk of Autism: Study

Certain antidepressants taken during pregnancy may increase the future's child's risk of autism, according to a recent study conducted by researchers at Drexel University.

Though researchers found the risk to be very small, previous studies have shown that selective serotonin reuptake inhibitors (SSRIs) and genetic factors associated with depression can increase the risk of  autism spectrum disorders (ASD).

For the study, researchers from the Drexel University School of Public Health analyzed population based registers of close to 750,000 births in Denmark from 1997 through 2006. Findings showed that about 1.5 percent of children born to women who had taken an SSRI during pregnancy had children who were were diagnosed with an ASD compared to about 0.7 percent of children born to otherwise similar groups of women not taking the medication.

"We found a two-fold increased risk for ASD associated with in utero exposure to SSRIs compared to the unexposed reference group" said lead author Nicole Gidaya, Ph.D., via a press release. "More importantly, in our analysis we accounted for under-reporting of maternal depression in the register. This suggests that under-reporting of the confounder, maternal depression, may be a limitation in approaches previously used in the other studies."  

However, researchers note that if there is a link between SSRI exposure during pregnancy and increased risk of ASD cases, it only represents a fraction of overall ASD cases. The study authors also cautioned against final interpretations of the results as distinguishing effects of medications versus those of the conditions could prove further complications. A larger study would needed to be conducted in order to further determine a more clear connection.

"As we complete research in our attempts to understand autism's causes we continue to realize that there are likely many genetic and non-genetic contributors," said Craig Newschaffer, Ph.D., director of the A.J. Drexel Autism Institute and professor in Drexel's School of Public Health, and the study's senior author. "We must begin trying to map these multiple risk factors on to common pathways, so that these pathways can be a focus in our effort to prevent the impairment associated with ASD.  Pathways involving the brain's serotonin system are still one viable candidate."

More information regarding the findings can be seen via the Journal of Autism and Developmental Disorders.