In parallel with a national school policy on an inclusive school with a marked reduction in the number of pupils who, due to their disruptive behaviour, are referred to educational provisions outside of the ordinary school environment, a sharp rise has been seen in the number of children and teenagers who are given a clinical diagnosis, first and foremost that of ADHD (Attention Deficit and Hyperactivity Disorders). Over just a few years, the skyrocketing of diagnoses has turned notions of children and teenagers with emotional and behavioural difficulties upside down. From being young people who should ‘just pull themselves together and behave properly’ many have become pupils with a neurological dysfunction that requires treatment. The article provides insight into how diagnoses over very few years have come into focus in schools and in special needs education, and how this has made a deep impression and changed understandings of the best possible special and general educational provisions for children and teenagers with behavioural and learning difficulties. The article focuses on trends in Denmark and therefore builds primarily on Danish sources.