The author of this test is not truly an expert on the subject, and makes many, many unsubstantiated claims. (Based not only on what I know of the subject compared to what he says of it, but also a wide variety of people's personal experiences with the guy, including my own. One of the most obvious claims I saw the guy make was that a friend of mine who'd never touched drugs, was actually a heavy abuser of drugs, when in reality he had an AS diagnosis. The guy refused to believe my friend was not a drug addict, when this friend has not even done prescription drugs, let alone what this guy was talking about.)
The scans that he uses to "diagnose" these types of ADD, are not approved for that purpose, although they are approved for other purposes (most of which he doesn't use them for). He has not made any effort to publish in serious scientific journals under controlled conditions, although other people have (and have found that in blind conditions the diagnoses are absolutely unreliable). Here are a couple articles on the subject:
http://www.quackwatch.org/06ResearchProjects/amen.html
http://www.quackwatch.org/06ResearchPro ... ponse.html
So, basically, the test is not only wrong (and the subtypes invalid), but also potentially dangerous, considering there are serious medical conditions that can cause some of these traits more likely than "a form of ADD" would.
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"In my world it's a place of patterns and feel. In my world it's a haven for what is real. It's my world, nobody can steal it, but people like me, we live in the shadows." -Donna Williams