Previous systematic reviews estimate the prevalence of attention-deficit/hyperactivity disorder (ADHD) worldwide as 5.6% to 7.2%.1,2 However, there is evidence that some ethnocultural groups, such as Black individuals, are underrepresented in studies.3,4 One systematic review found a higher prevalence of ADHD in Black than white youth, with evidence for a wide range in individual estimates for Black youth.3 Many factors may contribute to this variability.