Editorial: Can Physical Health Conditions in Childhood Predict Attention-Deficit/Hyperactivity Disorder Symptoms in...

In this issue of the Journal, Reed et al.¹ present compelling data on the cumulative effect that certain non-psychiatric health conditions, grouped by clusters according to physiologic mechanisms, could have on symptoms of attention-deficit/hyperactivity disorder (ADHD) in late adolescence. The study leverages data collected through the Millennium Cohort Study (MCS). The MCS is valuable to characterize longitudinal associations, as it follows the development of a well-characterized, population-representative sample of more than 19,000 individuals born in the United Kingdom (UK) between 2000 and 2002.^2,3 At the time of the study, 7 data sweeps had been conducted between 9 months and 17 years of age. Importantly, and as has been previously done with data collected through the MCS, standardized weights were applied to account for missing data from groups that are more likely to withdraw (eg, participants from disadvantaged backgrounds). As such, the sample represents the general UK population.