In The Politics of Autism, I discuss various ideas about what causes the condition.
Here is just a partial list of correlates, risk factors, and possible causes that have been the subject of serious peer-reviewed studies:
• Air pollution and proximity to freeways;
• Maternal thyroid issues;
• Autoimmune disorders;
• Induced labor;
• Preterm birth;
• Birth by cesarean section;
• Maternal and paternal obesity;
• Maternal and paternal age;
• Maternal post-traumatic stress disorder;
• Smoking during pregnancy;
• Antidepressant use during pregnancy.
Importance The association between the use of antidepressants during gestation and the risk of autism spectrum disorder (ASD) in children is still controversial. The etiology of ASD remains unclear, although studies have implicated genetic predispositions, environmental risk factors, and maternal depression.At Science, Emily Underwood writes:
Objective To examine the risk of ASD in children associated with antidepressant use during pregnancy according to trimester of exposure and taking into account maternal depression.
Design, Setting, and Participants We conducted a register-based study of an ongoing population-based cohort, the Québec Pregnancy/Children Cohort, which includes data on all pregnancies and children in Québec from January 1, 1998, to December 31, 2009. A total of 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 were included. Data analysis was conducted from October 1, 2014, to June 30, 2015.
Conclusions and Relevance Use of antidepressants, specifically selective serotonin reuptake inhibitors, during the second and/or third trimester increases the risk of ASD in children, even after considering maternal depression. Further research is needed to specifically assess the risk of ASD associated with antidepressant types and dosages during pregnancy.
[T]he “critical flaw” in the new research is that it doesn’t fully account for the fact that women suffering from psychiatric illnesses already have a greater risk of having children with ASD, says Roy Perlis, a psychiatric geneticist at Harvard University who consults for several biotechnology startups. Although the authors controlled for maternal depression, “they don’t really have reliable measures of severity,” he says. As a result, there’s no way to tell whether the children were at higher risk because their mothers were taking more drugs or because the women had more severe depression. Several papers, including two from Perlis’s group, have looked at large numbers of women and children and found no increased risk for ASD after adjusting for the severity of maternal depression, he says. “The risk travels with the disease, not the treatment,” he says.
Indeed, given the lack of evidence as to whether SSRIs and other antidepressants have any causal effect on fetal neurodevelopment, it’s possible that SSRIs could actually help a developing fetus whose mother is depressed, says Jay Gingrich, a psychiatrist at Columbia University who has no affiliations with any pharmaceutical companies. “Suffice it to say that there is a urgent need for more research into this area.”