A new study looking at the correlation of antidepressant use during pregnancy and the development of autism spectrum disorder (ASD) has been making headlines. While the results are likely significant, they are not as worrisome as the headlines may suggest.
The study: strengths and weaknesses
Overall the study design is solid. They followed 145,456 singleton full-term infants for a total of 904,035.50 person-years of follow-up. That is the strongest aspect of the study, its power. Typically when you capture large numbers you have to trade-off detail of information. As Lincoln might have said, you can capture a lot of information about a small number of people, or a small amount of information about a large number of people, but it is difficult to capture a lot of information about a large number of people.
The use of databases, especially in socialized countries, does help. In this case they used the ongoing population-based cohort, the Québec Pregnancy/Children Cohort. One compromise, however, is that they followed whether or not the mother filled a prescription for an anti-depressant. They did not capture whether or not the mother actually took the medication.