Antidepressants in pregnancy do not cause autism, study finds

New research cannot establish a close connection between the use of antidepressant medication - the so-called SSRIs - during the course of pregnancy and the risk of having a child with autism:

"More and more women are given antidepressant medication while they are pregnant. And an increasing number of children are diagnosed with autism. This has given rise to concern over a possible connection. In contrast to other, smaller studies, our survey cannot demonstrate that the risk of having a child with autism is increased by taking antidepressant medication during pregnancy," says PhD Jakob Christensen, researcher at Aarhus University and staff specialist at Aarhus University Hospital.

Previous research has shown that the risk of having a child with autism is up to five times greater for pregnant women who take antidepressant medication.

Largest study of correlation

In a large register study, Jakob Christensen and his colleagues from Aarhus University and Aarhus University Hospital have followed more than 600,000 Danish children born in the period between 1996-2006. The survey is the largest so far undertaken of the correlation between antidepressant medication during pregnancy and autism.

The initial results of the Danish study showed that there was almost a two percent risk of having a child with autism for pregnant women who take antidepressant medication during their pregnancy. For women who do not take antidepressant medication during pregnancy the risk was 1.5 percent. But the researchers also analysed siblings and parents' psychiatric diagnoses. And when these are taken into account the risk is shown to be minimal:

"We know from previous studies that there is an increased risk for autism, among other things, if the parents have a mental diagnosis such as depression. But we cannot demonstrate that the risk is further increased if the mother has received prescription antidepressant medication during the pregnancy," says Jakob Christensen, adding:

"By analysing data for siblings we can see that the risk of having a child with autism is largely the same regardless of whether the mother takes antidepressant medication or not during the pregnancy."

The researchers cannot thereby demonstrate that the medication is to blame for autism in children.

Important knowledge

Many women have antidepressant drugs prescribed by their general practitioner. Researcher in general practice Mogens Vestergaard believes that the survey also contains important knowledge for general practitioners:

"Most of the people who receive SSRIs get them through their general practitioner. This was also the case for 80 percent of the women who received antidepressant medication in the study. Of course the results of the survey provide important knowledge for the general practitioners. They are the ones who meet pregnant women who are nervous about the consequences of taking antidepressant medication during their pregnancy," says Professor Mogens Vestergaard from Aarhus University.

The researchers stress that there may be other risks associated with taking antidepressant medication during pregnancy. People should therefore contact their medical doctor in any case if they are under medication and considering becoming pregnant, so that they can receive the best possible advice.

The study has just been published in the internationally recognized journal Clinical Epidemiology.

Facts about the study

• Via the Danish CPR register, the researchers have followed all Danish children born between 1996-2006.

• A total of 655,615 children have participated.

• 8,833 children were exposed to antidepressant medication during pregnancy.

• During the period from 1996-2006, the number of pregnant women who took antidepressant medication increased from 0.5 percent to 2.5 percent.