In a groundbreaking study involving 145,456 pregnancies, researchers have found that the use of antidepressants during the second and third trimester may be a significant risk factor for autism. Currently around 4-7% of women take antidepressants during pregnancy to ease the debilitating symptoms of depression. Exposure to antidepressants during this critical time could almost double the risk of autism for their unborn babies, but this statistic needs to be understood in context.
We still aren’t clear on exactly what causes autism but there is robust agreement among researchers and professionals in the area that both genetics and environment are involved. We are aware of certain factors that may make children more vulnerable to autism, and exposure to antidepressants may be one of them.
Autism and Antidepressant Use During Pregnancy. The study.
The study was conducted by the University of Montreal and lead by Professor Anick Bérard, an expert on drug safety during pregnancy.
The researchers examined data from 145,456 pregnancies, which included information from the time of conception up to when the children were 10 years old. Because the data was so detailed, the researchers were able to isolate the specific effect of antidepressants on unborn babies by taking into account other risk factors that have previously been associated with autism including family history, mother’s age, and socio-economic factors (such as poverty).
The researchers then identified the mothers who had filled one or more prescriptions for antidepressants in the second or third trimester of pregnancy.
They then looked at the children in the study who had been diagnosed with childhood autism.
Once they had these two groups, they looked for an association between the two.
Mothers who had been exposed to antidepressants in the second or third trimester had an 87% increased risk of having a child with autism.
‘Our study has established that taking antidepressants during the second or third trimester of pregnancy almost doubles the risk that the child will be diagnosed with autism by age 7, especially if the mother takes selective serotonin reuptake inhibitors, often known by its acronym SSRIs.’ –Professor Anick Bérard.
The second and third trimester of pregnancy is a critical time for brain development and seems to be a particularly sensitive window for the effects of antidepressants to spill over to the unborn baby.
A warning: Don’t give up your meds just yet.
For anyone already taking antidepressants, it is critical that any pull back from medication is considered carefully in close consultation with a doctor. Sudden withdrawal from antidepressants can bring about other harmful side-effects, such as a worsening of the symptoms.
Putting it all in context …
Untreated depression has its own consequences. According to the World Health Organisation, depression will be the second leading cause of death by 2020. As well as the risk of suicide, untreated depression can also lead to poor sleep and poor diet, and emotional and physical stress which can also be harmful for a developing baby.
Bérard stresses that people should keep using their medication as needed, but suggests that if pregnancy is a possibility, it would be wise to explore other ways to treat the symptoms during pregnancy. Antidepressants are not the only option when it comes to finding relief from depression, and we are learning more and more about the lifestyle factors that are at least as effective as antidepressants. (See here). As Bérard explains, exercise and therapy have been shown to ease depressive symptoms for women whose depression is in the mild to moderate range, which describes most women who are prescribed antidepressants during pregnancy.
Dr. Bryan King, program director of Seattle Children’s Autism Centre emphasised the importance of putting the findings of the study into context,
‘… for every 200 mothers who continue their antidepressants through pregnancy, there may be one additional child born with autism.‘ -Dr Bryan King.
Berard also makes it clear that the findings from her research are intended to empower women by arming them with information, not scare them. This study is not about trying to convince women with depression to give up their medication, but about giving women the information they need to make the best possible choices for themselves and their babies.
The relationship between antidepressants and autism in this study is an association, not a causal relationship. There may be other factors involved that we are unaware of, such a other risk factors or conditions that need to be present.
‘A further problem with this and other studies is that we don’t know whether the risk signal that is being reported is due to the antidepressant exposure, or whether it reflects a genetic risk from depression. We know that some genes that appear to be associated with depression risk are also associated with autism risk.’ –Dr Bryan King.
Further research is needed to fully understand the relationship between antidepressants and autism and the mechanisms that are at play. In the meantime, it is important to understand the results in context of the broader picture and what it means in terms of the actual risk.
Like this article?
Subscribe to our free newsletter for a weekly round up of our best articles