Recent decades have witnessed the increased emergence and global application of medicalized meanings and practices related to mental health, with cases of contestation, adoption, as well as resistance observed. Such globalization raises a number of important sociological questions about the nature and consequences of such practices, as well as what they might mean for the changing nature of medicalization. Focusing on a classic case within medicalization studies, Attention Deficit Hyperactivity Disorder, this paper reviews existing insights on medicalization and mental health diagnosis and treatment in global context, future lines of inquiry, and related challenges.