Tuesday, 15 December 2015

Pregnancy antidepressant use and risk of offspring autism (again)

"Use of antidepressants, specifically selective serotonin reuptake inhibitors, during the second and/or third trimester increases the risk of ASD [autism spectrum disorder] in children, even after considering maternal depression."

That was the conclusion reported in the study by Takoua Boukhris and colleagues [1] dealing with a topic which has previously graced the autism research landscape (see here and see here). Detailing the results of a "register-based study of an ongoing population-based cohort, the Québec Pregnancy/Children Cohort" covering data on all pregnancies in Québec (Canada) between 1998 and 2009 (N=145 456 singleton full-term infants born alive and whose mothers were "covered by the Régie de l’assurance maladie du Québec drug plan for at least 12 months before and during pregnancy"), the Boukhris results have created quite the media stir.

Among the 140,000+ infants followed up, just over 1000 were eventually diagnosed with an autism spectrum disorder (ASD) equating to 0.7% of the population. When researchers looked at those who were prenatally exposed to antidepressants specifically during the second or third trimester of pregnancy, the rate of ASD was calculated at 1.2%. When also controlling for potentially confounding variables such as a maternal history of depression, the elevated risk of offspring autism persisted. Ergo, there may be more to see when it comes to antidepressant use during pregnancy and offspring developmental outcomes. I might also direct readers to an editorial discussing the findings [2].

Most of the media on this latest paper have been quite sensible about the findings. They've for example, pointed out that other research studies have reported slightly less in the way of any connection between pregnancy antidepressant use and offspring autism (see here) as well as putting the results into some context with the idea of what 'elevated risk' might actually translate into (see here). That also antidepressant use during pregnancy is not normally entered into lightly without good reason is something else that I'd bring into proceedings as per other research talking about other pregnancy medication use and potentially elevated risk to offspring outcomes (see here).

The authors do suggest that more research is required to build on their findings and "to specifically assess the risk of ASD associated with antidepressant types and dosages during pregnancy." I would agree that we do need more data on this possible association (including that from animal models and related studies) in order to ascertain whether specific medicine formulations might be more strongly involved and onwards the possible mechanism(s) of effect. I'm not necessarily sold on the idea that serotonin chemistry is specifically the be-all-and-end-all of any effect on the unborn child given what we are starting to realise about the wide-ranging effects of various medicines outside of that listed on the package insert (see here). I am willing however to entertain the idea that the further reaches of tryptophan metabolism might eventually come into the frame (see here). We await further studies.

Music now, and with the imminent launch of a certain Russian Soyuz rocket, a song for Tim...

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[1] Boukhris T. et al. Antidepressant Use During Pregnancy and the Risk of Autism Spectrum Disorder in Children. JAMA Pediatrics. 2015. Dec 14.

[2] King BH. Assessing Risk of Autism Spectrum Disorder in Children After Antidepressant Use During Pregnancy. JAMA Pediatrics. Dec 14.

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ResearchBlogging.org Boukhris, T., Sheehy, O., Mottron, L., & Bérard, A. (2015). Antidepressant Use During Pregnancy and the Risk of Autism Spectrum Disorder in Children JAMA Pediatrics DOI: 10.1001/jamapediatrics.2015.3356