Antidepressant Use While Pregnant Linked to Autism Risk

Seattle, WAYet another study suggests a risk of birth defects associated with using certain antidepressants while pregnant. Although this study does not examine Effexor birth defects or Effexor side effects in infants, the study does examine antidepressants similar to Effexor.

Effexor is in a class of antidepressants known as serotonin-norepinephrine reuptake inhibitors (SNRIs). They are similar to selective serotonin reuptake inhibitors (SSRIs) in that both affect levels of serotonin in the patient’s brain. SNRIs, however, also affect levels of norepinephrine. Some similar side effects have been found between the two classes of antidepressants, but that does not mean that all side effects found with one will be found with another.

A study conducted in Sweden (reported on by The New York Times; 4/22/13) suggests that the use of SSRIs or tricyclic antidepressants could increase the risk of having a baby with autism spectrum disorder. Researchers noted that it was not clear from the study whether it was the use of antidepressants while pregnant or the mother’s depression itself that was linked to the development of autism. They also noted that although the risk was higher when mothers took an SSRI and a tricyclic antidepressant, use of the medication resulted in only a very small percentage (0.6 percent) of the cases of autism spectrum disorder.

The study was published April 19 in BMJ (British Medical Journal). “The increased risk was observed with SSRIs as well as with other monoamine reuptake inhibitor (tricyclic) antidepressants,” researchers wrote. “All these increased risks seemed to be confined to autism spectrum disorders without intellectual disability and persisted after adjustment for several confounding factors.”

The study’s authors wrote that a previous study conducted in California found a twofold increase in the risk of autism spectrum disorder when the mother had a prescription for an SSRI during the year before pregnancy. That study did not include other antidepressants and involved only a small number of people.

“With the current evidence, if the potential risk of autism were a consideration in the decision making process, it may be reasonable to think about, wherever appropriate, non-drug approaches such as psychological treatments,” researchers concluded.

It is not clear if the same results would extend to SNRI medications. Although the drugs are similar and reportedly have similar side effects, it is possible that some side effects seen in SSRI antidepressants would not be seen in SNRI medications.