individuals enrolled in the Danish National Birth Cohort) and multiple child outcomes were included (Strengths and Difficulties Questionnaire [SDQ], medication use for ADHD, and hospital records for hyperkinetic disorder. Secondly, the longitudinal research was sampled prospectively, meaning that the results were unlikely affected by recall bias. Finally, the analyses controlled for a wide range of factors that might influence both medication- taking in pregnant mothers (e.g., reported fever, inflammatory problems) and ADHD symptoms in offspring (e.g., birthweight, antenatal smoking and alcohol use).
In an Editorial in the same issue of JAMA Pediatrics, Cooper et al. [6] underscore the importance of the acetaminophen findings but also highlight some of the study weakness. They rightly stress that the correlational design of the study (among other factors) does not permit us to infer causation. As such, the authors urge caution when interpreting the study results until the findings are replicated and extended. One such recommendation by the authors to extend the study was to examine other drugs taken during pregnancy to determine if the drug-ADHD association was specific to acetaminophen.
Towards this end, the aim of the present study was to determine the association between drugs commonly taken during pregnancy, including acetaminophen, and ADHD in child members of the prospective Auckland Birthweight Collaborative (ABC) longitudi- nal study. Aspirin, antacids, and antibiotics were the other drugs, besides acetaminophen, that were analysed in relation to SDQ total difficulties (and sub-scales) at 7 and 11 years of age. We also measured ADHD symptoms with more specificity than the SDQ by using the Conners’ Behavioural Rating Scale: Revised (CRS:R) parent report at ages 7 and 11 years. Our analyses included multiple covariates, including those controlled for in the Danish study. We also included other factors previously shown to be related to SDQ in our study, including antenatal maternal perceived stress. Children of mothers who report antenatal stress have been shown to have a range of poorer neurodevelopmental outcomes, including ADHD [7,8].