Around 14 per cent of American children and adolescents are taking ADHD (attention-deficit hyperactivity disorder) drugs such as Ritalin and Adderall. The drugs are stimulants that have a paradoxical calming effect on hyperactive children—but they are also being abused or misused by the children or other children in the home.

Deliberate abuse accounted for half of all the cases among teenagers that were reported to poison centres, and medication errors—including overdose or taking the drugs too frequently—were responsible for most of the cases in children up to the age of 12.