The VOICES (Voices On Identity, Childhood, Ethics & Stimulants: Children join the debate) study investigated claims about the ethical harms of attention deficit hyperactivity disorder (ADHD) diagnosis and stimulant drug treatments. We focused on three ethical concepts: authenticity, moral agency and moral responsibility. We also investigated children’s perspectives on broader societal concerns about behavioural norms and childhood experiences; schooling expectations and academic pressures; and stigma associated with ADHD. In this article, we report on the finding that ADHD was viewed and experienced by diagnosed children in different ways in the USA and UK. We discuss the different forms of stigma experienced in these two countries and we show the close association between stigma and contextual understandings of ADHD. We argue that medical professionals should do more to directly engage with their paediatric patients to better understand, and to help combat, stigma.