In most cases ADHD is diagnosed by observation of behaviours. This has led some people to doubt that ADHD is a real disorder. Maybe it is just rowdy young people that parents want medicated to make their lives easier.
A new study has compared the brains of adults who grew out of ADHD with adults who still have ADHD. There was a real difference in their brains. You can read about it here. This demonstrates that there is indeed a biological basis for ADHD.
