Prenatal exposure to selective serotonin reuptake inhibitors (SSRIs) during the second or third trimester raises the risk of autism spectrum disorder (ASD) in children 87%, according to a new study in the online JAMA Pediatrics.
Researchers came to their finding after reviewing data for 145,456 children born in Quebec 1998 to 2009. In their analysis, the researchers wrote that they considered potential confounders such as maternal age, maternal depression, and exposure to poverty, all of which are associated with autism.
By age 7, children exposed to SSRIs during the second or third trimester had almost double the risk of an autism diagnosis, they found.
"It is biologically plausible that antidepressants are causing autism if used at the time of brain development in the womb, as serotonin is involved in numerous pre- and postnatal developmental processes, including cell division, the migration of neuros, cell differentiation and synaptogenesis—the creation of links between brain cells," said researcher Anick Bérard, PhD, the University of Montreal and CHU Sainte-Justine Children’s Hospital. "Some classes of anti-depressants work by inhibiting serotonin (SSRIs and some other antidepressant classes), which will have a negative impact on the ability of the brain to fully develop and adapt in-utero."
Almost immediately upon publication, however, the study drew backlash from experts who said it was flawed.
The flaw, explained a psychiatric geneticist in a news report on the website of the journal Science, is that the research fails to fully account for the fact that women diagnosed with psychiatric disorders are more likely to have a child with autism spectrum disorder. While researchers said they controlled for depression in mothers, Roy Perlis, MD, Harvard University, told Science “they don’t really have reliable measures of severity.” Consequently, it is impossible to understand if the risk was greater due to SSRI use or more severe depression in the mother, he said.
The study’s concluding recommendation—that women with mild to moderate depression avoid antidepressants if possible—was also widely criticized.
“Some say that’s a misleading and potentially dangerous conclusion, given two factors: the relatively low incidence of autism spectrum disorder in the general population and the fact that maternal depression—which can lead to poor sleep and eating patterns—can lead to greater health risks for unborn children,” the Science article explained.
“Incidence in the general population is about 1%, for example, so an 87% increase in autism spectrum disorder risk due to SSRI use would raise a child’s absolute risk of developing autism to roughly 2%.”
1. Boukhris T, Sheehy O, Mottron L, Bérard A. Antidepressant use during pregnancy and the risk of autism spectrum disorder in children. JAMA Pediatrics. 2015 Dec. 14. [Epub ahead of print].
2. Taking antibiotics during pregnancy increases risk of autism by 87 percent [press release]. EurekAlert!: Washington, DC; Dec. 14, 2015.
3. Underwood E. Reality check: taking antidepressants while pregnant unlikely to double autism risk in kids. Science. Dec. 14, 2015.