Kim KM, Choi YJ, Lim MH, et al. - Researchers aimed at determining how parental age at birth is associated with attention-deficit/hyperactivity disorder (ADHD) symptoms in their children. Participants were a total of 30,552 children aged 6–12 years. Using the Korean version of the ADHD Rating Scale (K-ARS), parents rated ADHD symptoms. Based on the age of both parents at birth, K-ARS scores and odds ratio (OR) for children with high-risk ADHD presented a U-shape curve. Children of fathers and mothers belonging to the youngest age group (aged ≤ 20) exhibited the highest total K-ARS scores and OR for high-risk ADHD; these were second highest in children whose father's or mother's age at birth was the oldest  (≥ 41 years). Per these findings, both spectrums of age—young and old of either parent—were linked with ADHD in children.