They can be harmful, but diagnosed ADHD/ADD is almost guaranteed to be harmful, maybe especially in todays society. More than doubled risk of depression is only one of the risks of the above diagnoses, and while many of the risks could be said to be more of a societal issue - at least in the beginning - they tend to cause actual health problems over time. Overprescription can always be an issue for any medication, but that's not really an issue with the medication itself is it ?