Previous reports might have overestimated the association between gestational use of antidepressants and ADHD in offspring because they have failed to control for shared family factors. Although we cannot completely discount the possibility that gestational use of antidepressants is a causal factor, our findings raise the possibility that confounding by indication might at least partially explain the observed association. We propose that if a causal association exists, then the size of the effect is probably smaller than that previously reported. However, decision making about antidepressant use in pregnancy remains important and requires an assessment of the risks and benefits in the context of the individual woman and family.
What is already known on this topic
- Whether to prescribe drugs for depression during pregnancy is a complex decision
- Prenatal use of antidepressants is considered a risk factor for attention-deficit/hyperactivity disorder (ADHD) in children, but evidence is inconclusive
- The negative consequences of untreated maternal depression might also affect childhood development
What this study adds
- The risk of ADHD was similar between the offspring of mothers who used antidepressants during pregnancy and those who used before pregnancy only, whereas the risk was higher for offspring of mothers with psychiatric disorders irrespective of whether antidepressants were used
- Evidence suggests that the association between prenatal antidepressant use and risk of ADHD may at least partially be explained by confounding by indication of antidepressants
- If there was a causal association; then the size of the effect is probably smaller than what has been reported previously
2017 Study Abstract
To assess the potential association between prenatal use of antidepressants and the risk of attention-deficit/hyperactivity disorder (ADHD) in offspring.
Population based cohort study.
Data from the Hong Kong population based electronic medical records on the Clinical Data Analysis and Reporting System.
190 618 children born in Hong Kong public hospitals between January 2001 and December 2009 and followed-up to December 2015.
Main outcome measure
Hazard ratio of maternal antidepressant use during pregnancy and ADHD in children aged 6 to 14 years, with an average follow-up time of 9.3 years (range 7.4-11.0 years).
Among 190 618 children, 1252 had a mother who used prenatal antidepressants. 5659 children (3.0%) were given a diagnosis of ADHD or received treatment for ADHD. The crude hazard ratio of maternal antidepressant use during pregnancy was 2.26 (P<0.01) compared with non-use. After adjustment for potential confounding factors, including maternal psychiatric disorders and use of other psychiatric drugs, the adjusted hazard ratio was reduced to 1.39 (95% confidence interval 1.07 to 1.82, P=0.01). Likewise, similar results were observed when comparing children of mothers who had used antidepressants before pregnancy with those who were never users (1.76, 1.36 to 2.30, P<0.01). The risk of ADHD in the children of mothers with psychiatric disorders was higher compared with the children of mothers without psychiatric disorders even if the mothers had never used antidepressants (1.84, 1.54 to 2.18, P<0.01). All sensitivity analyses yielded similar results. Sibling matched analysis identified no significant difference in risk of ADHD in siblings exposed to antidepressants during gestation and those not exposed during gestation (0.54, 0.17 to 1.74, P=0.30).
The findings suggest that the association between prenatal use of antidepressants and risk of ADHD in offspring can be partially explained by confounding by indication of antidepressants. If there is a causal association, the size of the effect is probably smaller than that reported previously.