Kase BE, Rommelse N, Chen Q, et al. - Given that attention-deficit/hyperactivity disorder (ADHD) and obesity are 2 frequent conditions that co-occur, which has implications for the management of both conditions, experts aspired to explore whether ADHD symptoms predict BMI and vice versa from late childhood (10–12 years) up to early adulthood (20–22 years). Participants were adolescents from the Tracking Adolescents’ Individual Lives Survey cohort in the Netherlands (n = 2773, 52.5% male, mean age = 11 years at baseline, 5 waves up to mean age 22). The relationship between ADHD and BMI remains stable throughout adolescence, and it is associated with hyperactive and impulsive symptoms rather than inattention. During this developmental period, there was no direct relationship between ADHD symptoms and BMI increase, nor between BMI and enhanced ADHD symptoms. The findings point to a shared genetic or familial background and/or potential causal effects established earlier in childhood, implying that intervention and prevention programs targeting overweight and obesity in children with ADHD should be implemented as early as possible.