AutismSpectrumDisorder (ASD) is a broad sense of autism based on an expansion of the core symptoms of classic autism to include both classic autism and disorders such as Asperger’s syndrome. Although studies have suggested that genetic predisposition, environmental risk factors, and maternal depression may be associated with ASD, the exact etiology has not been clarified. Currently, there is controversy over the association between ASD in children and the use of antidepressants by their mothers during pregnancy. Recently, Takoua Boukhris et al. from the University of Montreal, Canada, conducted a large, population-based maternal/child cohort study, also the first to examine the impact of maternal history of depression and psychiatric co-morbidities, which was published in the journal JAMA. Data from the study included information on all pregnant women and children in Quebec City from January 1, 1998, to December 31, 2009, with a total of 145,456 full-term singletons whose mothers had received antidepressant treatment for at least 12 months before or during pregnancy. Fetal antidepressant exposure was then categorized according to trimester of pregnancy and type of medication. Screening criteria for children with ASD: at least one medical diagnosis of ASD from birth to the survey deadline.Data were analyzed using Cox proportional risk regression models to estimate raw and adjusted risk ratios with 95% confidence intervals. Of all eligible study participants, 0.7% of children were diagnosed with ASD, with a male-to-female ratio of 4:1 and a mean age of 6.24 years. After adjusting for potential confounders, analysis of the data showed that maternal antidepressant use in the second and third trimesters was associated with an 87% increased risk of ASD in children. Strong associations were seen when mothers took SSRIs or a combination of antidepressants. However, medication in the first trimester and the first year of pregnancy did not increase the risk of ASD in children. This risk remained when the mother’s history of depression was excluded. Analysis of the data also showed that mothers who took antidepressants during pregnancy were more likely to have psychiatric disorders and co-morbidities, were older, and had a higher probability of giving birth to another child with ASD. TakouaBoukhris et al. also conducted sensitivity analyses, and after adding the restriction that the child was diagnosed with ASD by a psychiatrist or neurologist, correlation analyses found a higher correlation between mothers’ use of antidepressants in the second or third trimester and the child’s development of ASD. However, the results were not statistically significant due to insufficient sample size. Why does maternal use of SSRI antidepressants increase the risk of ASD in children? Studies have shown that SSRIs can cross the placenta into the fetus and have effects on fetal neurological development, including cellular differentiation, neuronal migration, cellular differentiation, and protrusion formation. There is evidence that children with ASD have hyper-hydroxytryptaminemia and have altered levels of brain synthesis of serotonin, as well as altered serotonin receptor 2A binding in the cerebral cortex. However, the study had some limitations. The data were based on doctor’s prescriptions, which are not fully representative of the actual medications taken by the pregnant women, and information on the lifestyle habits of the pregnant women was not well collected, which may have affected the results of the study. In conclusion, the use of antidepressants, especially SSRIs, during the second and third trimesters of pregnancy increases the risk of ASD in children. Further research will need to clarify the extent to which the type and dose of depressant medication affects this risk.