Imagine you are a teacher standing in a classroom in front of a group of children. One of them can not sit still. His legs are kicking under the table; his gaze is unfocused as he looks at the pages of his textbook. He gets up and takes a pencil from the next desk, and when his classmate complains, the restless boy explains loudly that he forgot his own pencil case. Everybody stares at him, but he keeps talking, until he walks out of the room in frustration, leaving the door open behind him.
Such situations are common, but how should a teacher respond? This is highly debated. Not long ago the boy might have been characterised as badly behaved, with tough discipline as the remedy. Today he would probably be diagnosed with the mental health disorder ADHD, and might be a candidate for medical treatment.
The disorder ADHD is characterised by hyperactivity, impulsivity, and problems with concentration. It has become far more common in recent decades, with part of the explanation being
