Aside from academic issues it seems that ADHD/ADD, like many treatable mental conditions, are over diagnosed simply to secure the treatment fees and the associated profit. This is not limitted to only medical/mental health professionals but pubic schools as well - the public school gets extra federal fundung for each such "special needs" student from the federal gov't.
With recent talk of adding those with mental/behavioral "problems" to the NICS (national "criminal" database) used for gun rights determination, extreme caution should be exercised in getting such a diagnosis. While it may help those in their early years it may have lasting repercussions later in life as well.
I am of mixed feelings when it comes to mental/behavioral issues; while many may be correctly diagnosed and successfully treated, it seems that many (more?) are simply given "happy pills" to reduce the burden of many natural tendencies of some to be more unruley than "normal". After all, if it an illness then no personal blame/responsibility can be assumed for adding to or not properly dealing with that condidtion/deficiency.