My favorite on the subject of children w so-called behavioral disorders, ADD, ADHD, etc. are the audios.
Perhaps your friend is already aware of something we now like to call Asperger Syndrome, but I post a couple links for the record. I watched emerge from age 4 to 14 a dear friend's child who exhibited similar behavior to what you describe. He truly has Asperger, as did/does Bill Gates. Brilliant children are trapped behind an often peculiar, sometimes volatile, socially unacceptable but intensely willed/driven personality during these years and are usually, particularly early on, quasi-misdiagnosed as ADD, ADHD, autistic. etc.
I personally don't like labels, and i definitely don't like mondays now/either/also. : (