Can an increased risk of autism be linked to Paxil?

Late last year, a study was published in the Archives of General Psychiatry that suggests a possible link between autism spectrum disorders (ASDs) and maternal use of antidepressant medications during pregnancy. The study—although inconclusive as to a causal link between the two—has gotten quite a bit of attention for the advances it makes in furthering our understanding of what causes ASDs.

The study was aimed at determining whether prenatal exposure to antidepressant medications can be associated with an increased risk of ASD. It was a relatively small study, involving only about 300 children with ASD and 1500 randomly selected children without ASD. The authors concluded that the results suggest that exposure to SSRIs—especially during the first trimester—may “modestly increase the risk of ASD.” The researchers also underscored the need for further studies on this issue, particularly given this study’s small size.

The antidepressant drugs examined in the study belong to a class of drugs known as selective serotonin reuptake inhibitors, which includes such commonly known medications as Zoloft, Prozac, Paxil and Celexa. Thousands of women who suffer from depression are on these types of medications—so what does this study mean for them? It may be too early to say, and researchers are urging caution with over-interpreting the results of the study. The study did not establish a clear causal connection between the drugs and ASD. In fact, it is possible that the ASD is caused by the underlying disorder of depression and not the treatment. In addition, there are serious risks to the fetus if depression goes untreated during pregnancy.

In addition, exposure to SSRIs during fetal development is certainly not the only prenatal risk factor for developing an ASD. Another study from 2009, published in the British Journal of Psychology conducted a comprehensive review of 50 risk factors that have been the subject of study. And besides prenatal medication in general, the study pointed to advanced maternal and paternal age at birth; maternal gestational bleeding; gestational diabetes; birth order; and maternal birth abroad as other factors associated with a higher incidence of ASD.

The cause of ASDs continues to escape scientists who are researching the issue. But, with each new study, we get closer to pinning down the specific risk factors. For now, the take-away for expectant mothers on medications for other health issues is to carefully discuss these issues with their physicians. SSRI drugs have an important role to play in producing healthy outcomes for the mother, but more and more research is mounting that they may be bad for the fetus.